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Introduction to jQuery Selectors

When working with JavaScript, you will often find yourself in a situation where you must find and modify some content on the page. In these cases, you must use the selector support in JQuery. JQuery makes it quite easy to find page elements based on their types, values, attributes, etc. These elements are based on CSS selectors, and once you have had some practice, you will see that finding elements in the pages is a cakewalk. Depending on their use, we can classify different types of JQuery Selectors for other kinds. Let’s take a look at some of the most used selectors.

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Using a Selector

Following is a syntax of a JQuery Selector:


If you need, you can chain multiple selectors by adding a “.” Between the methods.

$(selector).method1().method2().method3(); Types of Selectors in JQuery

Here are the different types of Selectors in JQuery.

1. Basic JQuery Selectors

We can select page elements using their ID, Class, or tag names. If needed, a combination of these can also be used. Following are some basic selectors:

: header Selector — This basic selector type lets us find elements with their HTML headings. To do this, we use the verbose $ (“section h1, section h2, section h3”) selector, or we can also use the much shorter $(“section :header”) selector.

:animated Selector — This selector is used to find all animation elements. Remember that for the animation to be selected, it has to be running when the selector is run.

2. Selectors based on Index

:eq(k) Selector — This selector returns the element at index k. It supports negative index values too.

:lt(k) Selector — This selector returns all elements with an index less than k. As above, negative values are also accepted

:gt(n) Selector — This selector is similor: lt (k) Selector except it works for Index values greater than or equal to k.

3. Child Selectors

You can use JQuery to select children of any element based on their type or index.

:first-child — This selector will return all elements which are the first child of their parents.

:first-of-type — This JQuery selector selects all elements that are the first sibling

:last-child — As the name suggests, this selector will select the last child of the parent.

:last-of-type — This will select all children that are last of their type in a parent. If there is more than one parent, it will select multiple elements.

:only-of-type – We can use the only-of-type selector to find all elements with siblings of the same type on the page.

:only-child – In situations where you need to find and select elements that are the only child of their parent, you can use this selector. If a parent on the page has more than one child, it will be ignored.

4. Attribute Selectors

Elements can be selected based on their attributes; the following are some common attribute selectors:

$(“[attribute~=’valuehere’]”) — This returns all elements with attributes where the value contains a given the word delimited by spaces.

$(“[attribute*=’valuehere’]”) — It will select elements where the value contains the given substring. As long as the value matches, the location won’t matter

5. Content Selectors

As the name suggests, these JQuery Selectors find and select content inside elements.

:contains(text) — This selects elements with specified text content inside. One thing to remember when using this selector is that the test here is case-sensitive.

:has(selector) — It will return elements with at least one element inside that matches the specified selector. For example, $(“section:has(h1)”) will return with all sections that have an h1 element.

:empty — This selector will return the elements of the page that don’t have any children, including text nodes.

:parent — This selector selects all the elements of the webpage that have at least one child node. You can consider it as an inverse to the: empty JQuery Selector.

6. Hierarchy selectors

$(“ancestor descendant”) – It selects all the descendant elements of a parent. In our case, the descendant could be a child, grandchild, and so on.

$(“previous + next”) – In case we need to select all elements that match the “next” selector and that have the parent “previous”. The selected elements will also be immediately preceded by “previous, ” the sibling.

7. Visibility Selectors

Two selectors: visible and: hidden, are also available in JQuery. These finds visible or hidden elements on the webpage. Any element in the webpage is considered hidden if:

Its display properly is set to none.

Its width and Hight are defined as zero.

It has type=hidden mentioned in the form element.

Any ancestors of the element are already hidden.

8. Form Selectors

JQuery has sorter versions of selectors for input elements of web forms to save time and hassle.

For example, while $ (“button, input[type=’button’]”) will work to select the button on the page, we can use $ (“:button”) to do it quickly.

Similarly, we can use $ (“: radio”) to select the radio button.


Selectors are one of the important features of JQuery, the selection on JavaScript is not as intuitive and robust, but with the addition of selectors via JQuery, programming for the web has become easier.

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Learn 6 Major Types Of Manual Testing

Introduction to Manual Testing

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Manual Testing on Software

The software can be tested in two ways by a human manually and automatically by a computer. Each technique has its benefits and drawbacks but shares the fundamental objective of maintaining software quality. We will concentrate on manual testing in this article.


Below are the six types described below.

1. White Box Testing

The software testing strategy includes black box testing and white box tests. Here we discuss white-box tests, referred to as “glass box” tests, structural tests, and clear box tests, and open box tests. It tests inner coding and software infrastructure to verify predefined inputs on anticipated and desired outputs. It is based on an application’s inner functioning and revolves around testing the internal framework.

The programming abilities needed for this sort of testing are the design of test instances. The main objective of white-box testing is to concentrate on the flow of inputs and outputs via the software and to strengthen software safety. Due to the inner system view, the word “white box” is used. The clear box or name of the white box indicates the capacity to look inside the software’s external shell.

2. Black Box Testing

Black Box Testing is a software test method that examines the software’s functionality without looking into its inner structure or coding. A specification of the needs indicated by the client is the main cause of black-box testing. This technique is used to choose a feature and provide an input value to check whether the function provides an anticipated performance.

If the feature yields the right output, it will be tested if otherwise, it will fail. The test team reports the results and then tests the next task. After all, features have been tested, if serious issues occur, the development team will be returned for correction.

3. Integration Testing

Integration Testing is the second stage after unit testing of the software testing method. Units or individual software components are being evaluated in a group during this test. The integration test level focuses on exposing flaws when parts or units are interacting.

Unit testing utilizes test modules, which are combined and tested during integration testing. The software is designed with a number of software components written by various programmers or coders. The objective of integration testing is to verify that communication between all modules is correct.

4. Acceptance Testing

Acceptance tests are official tests based on user requirements and the handling of functions. It determines whether or not the software complies with specific customer demands. It is done as a sort of Black Box test where the necessary amounts of customers participate in the system acceptance test. It’s software testing’s fourth and last level.

But there are still minor mistakes to identify when the system is in the current scenario used by the end-user. The software has now gone through three stages (unit testing, integration testing, and system testing) where changed requirements are present and can not be efficiently conveyed to the development team during the growth of a project.

5. Unit Testing

Unit testing includes the inspection of each software unit or element. It’s the first software test level. The objective behind unit tests is to validate the efficiency of the unit element. A device is one test component of a computer scheme and has been tested during the application software design stage. This test is to check the accuracy of the isolated code. A single function or application code is a unit element.

Testing approach White Box used by designers for unit testing. Unit tests are the first level of tests performed prior to inclusion and other test concentrations in a test level structure. The testing method utilizes modules that reduce the unit testing frames’ reliance on stubs, drivers, and mock items to help in unit testing.

6. System Testing

System testing involves testing the software system completely integrated. Software integration is generally produced by a computer system (every software is only one computer system component). The software is created in units and then interfaced to produce a full computer system with other software and hardware. In other words, a system consists of a group of software for the performance of various functions, but software alone can not accomplish the job.

System testing is a sequence of distinct types of trials for carrying out and testing against demands for the complete functioning of the embedded software computer system. System testing is tested in Black Box as it involves testing the software externally. The testing of minor defects follows the user’s viewpoint.

How to Perform in Manual Testing?

Read the project documentation/guides software and comprehend it. If available, also study the Test Application (AUT). Draft test cases covering all of the documentation demands. Check and reference Team Lead, Customer test cases (as appropriate) Once bugs have been corrected, run the failed test instances again to confirm that they have passed. Black box testing and white box testing is used to perform all test instances manually.

Differences Between Manual and Automation Testing

Automation Testing involves using testing tools Manual testing needs intervention by human beings for testing. Whereas it requires a qualified workforce, long time, and expenses.

Some test kinds like ad hoc and monkey testing are more suitable for manual execution, and any request can be tested manually. Automated tests are only suggested for stable systems and are mainly used for regression testing.

Automation software for automation testing is used for the boring portion to perform the same test instances time and again. Repetitive and boring manual testing can become.

Below are the pros and cons explained.


• The new user can learn very easily

Tools to Perform it

Now we’re going to see some of the tools below:






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Wildcard Selectors ( And ) In Css For Classes

In CSS, selectors are used to selecting the elements by class name, id, tag, etc. There are also some wildcard selectors available in CSS, which we can use to define the queries to select the HTML elements.

Wildcard selectors allow us to select an HTML element containing the particular substring in the value of the particular attribute, such as class or id. In this tutorial, we will learn to use the *,^, and $ wildcard selectors for classes and id.

Contains (*=) wildcard selector in CSS

The contains (*=) wildcard selector allows developers to find all HTML elements whose attribute value contains the ‘string’ as a substring. For example, using the ‘*’ wildcard selector with the class finds all HTML elements whose class name contains the string.


Users can follow the syntax below to use the contains (*) wildcard selector for classes.

[class*="string"] { }

The above syntax selects all HTML elements containing the ‘string’ as a substring in the class name.


In the example below, we have created the four different div elements and added the texts inside that according to its class name. In CSS, we have used the ‘contains’ wildcard selector to select all div elements whose class name contains the ‘test’ as a substring.

In the output, users can observe the colour of the first two div element’s texts is red as it contains the class name with the ‘test’ substring.

[class*=”test”] { color: red; font-size: 2rem; }

Starts with (^=) wildcard selector in CSS

The starts with (^=) wildcard selector allows us to select all HTML elements whose attribute value starts with the particular substring.


Users can follow the syntax below to use the starts with wildcard selector for classes.

[class^="string"] { }

The above syntax selects all HTML elements whose class name starts with the ‘string’.


In the example below, we have used the starts with (^=) wildcard CSS selector with the class to select elements based on the class name.

In the output, users can observe that the first and third div element’s text turns blue as it contains the ‘test’ string at the start. The second div element contains the ‘test’ in the class name, but it is at the end of the class name, so it is not selected by the starts with (^=) wildcard selector.

[class^=”test”] { color: blue; font-weight: bold; }

Ends with ($=) wildcard selector in CSS

The ends with ($=) wildcard selector selects all HTML elements if a particular attribute value contains the substring at the end. For example, if the class names of two different elements are ‘onestart’ and ‘lastone’, and the substring is ‘one’, it will select an HTML element with only the ‘lastone’ class name as it contains the one substring at the end.


Users can follow the syntax below to use the ends with ($=) wildcard CSS selector for classes.

[class$="string"] { }

The above syntax selects all HTML elements whose class name ends with the ‘string’ substring.


In the example below, 2nd and fourth div elements contain the ‘test’ substring at the end in the class name value. We have used the ends with ($=) wildcard CSS selector to select both div elements and applied border, margin, and padding to them.

[class$=”test”] { border: 2px solid pink; padding: 5px 10px; margin: 5px; }


In the example below, we use id with the ends with CSS selector rather than using the class as an attribute. It demonstrates how to use other attributes with the wildcard CSS selector to select HTML elements.

Here, we select all HTML elements whose id contains the ‘name’ at the end of its value and change font style and colour.

[id$=”name”] { color: lightskyblue; font-style: italic; font-size: 1.5rem; }

Users learned to use the wildcard CSS selectors for classes. Users can use the contains (*=) CSS selector to get elements whose attribute value contains a substring in the middle, starts with (^=) CSS selector to get elements whose attribute value contains a substring in the start, and ends with ($=) for the end.

Also, users learned how to use wildcard CSS selector with other attributes such as an id in the last example.

Learn How Does Azure Monitor Work With Its Types?

Introduction to Azure monitor

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What is an Azure monitor?

The Azure monitor supports the user to achieve maximum performance in services and applications. As discussed above, the below points stress the necessity and application of Azure monitor. It diagnoses and detects the bug in any application with its feature called application insights. It can compare the infrastructure flaws with container and VM insights. Then it can penetrate the application and monitor data with analytical log details to troubleshoot and work on deep insights. It supports operations at a finite scale by using its automated actions and smart alert systems. Finally, it can develop visualization with workbooks and Azure dashboards.

How does Azure monitor work?

The infrastructure of the Azure monitor has a high-level view. The metrics and logs are placed at the center of the Azure monitor, which works on two important types of information used by the Azure monitor. In the right of the Azure monitor, there are resources to work on the data monitoring events which populate the data stores. On the other end, Azure monitor work on different functions which work on the collected data. It also performs alerting, analysis, streaming, and other actions to its external connected systems.

In simple, it can be termed as: Azure monitor gathers the information from different sources like operating systems, applications, various resources of Azure in the formats of logs and metrics. It can then be processed to work on different functions like visualization, automation, integration, alert systems, and deep analysis.

Metrics are coined as a measurement to view aspects of resources. For example, it helps to check on the number of connections, disk IOPS, CPU utilization, swap space, memory utilization, etc. It is real-time and saved as a finite value with a periodic collection interval. Therefore, it is adapted to the environment better, and the collected logs are displayed as graphs concerning time and performance.

Logs are a collection of records with metadata and different properties that have a simple structure and provide an organized view of the SQL database. It is comprised of numerical information like metrics which has brief text with extra information. Traces and events are the best examples of logs. It is a dash of data that periodically collects the data which needs to be manipulated to view. The user wants to extract and filter the data from the logs by using a native query called kusto query language. It can be used to produce some logical visualization, and it can be pinned to dashboards.

Azure Monitor types collect

Application data: The information about the compiled code’s functionality and performance irrespective of any platform is collected from the application monitoring data.

Operating System data: The information about the operation system on which the user is hosting the application is collected in Guest monitoring OS data. It can be another cloud, Azure, or on-premise.

Resources on Azure data: The information about the process of an Azure resource is collected in Azure resource monitoring events.

The subscription on Azure data: Azure’s proper health check process manages the information about the management and operation of subscriptions in Azure.

Key requirements

The alert system is one of the key requirements for Azure monitor. It proactively alerts the user when the application is facing critical conditions and requires some corrective actions. The alert rules depend on metrics provided in real-time based on numerical values. In addition, it is based on logs which enable solving complex logic across the data from multiple resources.

Azure monitor application insights

Monitoring the information is useful only if it enhances the visibility of the process in the computing environment. The insights offer a customized monitoring experience for a few particular services. It provides minimal configuration and enhances visibility in the area of critical resources. Application insight always monitors the performance, availability, usage, swap space, and memory allocation of the web application deployed on on-premise or cloud. It structures the powerful data in the Azure platform to offer the user a deep view of the application’s performance. It allows the user to detect errors without any delay and report them to him. The application insight enables different points in development tools and combines them with visual studio to support the process in DevOps.

Azure Monitor Visualizing monitoring data

The visualization in Azure monitor offers tables and charts as effective tools for succinct the monitoring data to display it to a different set of audience. In addition, it has its features to visualize the monitoring data and structure the services of Azure to telecast to the audience. Apart from charts and tables, the monitor has attractive dashboards, workbooks, and power BI to consolidate the performance of the application and display it to the user for better understandings.


Once the Azure subscription is activated, the azure monitor performs and monitors all the addition of resources like web applications and virtual machines. The Azure monitoring begins to collect the data, and the activity logs are recorded when all the resources are developed or edited. The metrics explain the performance of the resources. The diagnostics enable options to allow the user to maximize the availability of the data, and the agent addition option is there to compute the resources to gather info from telemetry from guest OS.

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Examples For Queryselector() In Various Properties

What is jQuery querySelector?

jQuery querySelector is used for selecting a specific document object model (DOM) element from the HTML document, using the HTML elements like name, id, attribute, type, attribute values, class, etc. This selection activity is performed with the help of the query querySelector() method, which is used to fetch the return value as the first value identified in the CSS selector document. This function is for performing multiple operations and is known amongst the programmers for it’s the faster processing time, smaller & plain javascript code, and easier to code as well.

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Introduction to querySelector

The querySelector() method only returns the first element that matches a specified CSS selector(s) in the document. If an ID in the document is used more than once then it will return the first matching element.

Syntax of querySelector querySelector(CSS selectors)

It returns the first element that matches the specified selectors.

To return all the elements which match then we use the querySelectorAll() method.

The CSS selectors which we pass should be of string type.

It is mandatory to pass the CSS selectors.

The string which we are passing must be a valid CSS selector.

If the passed string is invalid then an SYNTAX_ERRexception is thrown.

If no match is found it will return null.

The matching of the first element is done using a depth-first pre-order traversal of the document.

Specifies one or more CSS selector to match the element.

For multiple selectors, separate with a comma.

Characters that are not part of standard CSS syntax must be escaped using a backslash character.

Examples for querySelector() Method

Below are the examples for querySelector() methods:

In jQuery, you can select elements in a page using many various properties of the element they are Type, Class, ID, Possession of Attribute, Attribute Values, etc. Below is the example of Jquery by using type.

Example #1 – Selecting by type

Explanation of the above code: In this example, we can observe that we have used two anchor tags and inside the anchor tag we have passed the hyperlink of two images. By using the querySelector(“a”).style.backgroundColor = “red”; we have passed the anchor tag (“a”) to the querySelector. In the querySelector() method if we pass the multiple selectors it will return the first element that matches the specified selectors. Though it contains two anchor tags the first anchor tag which is found, applied its style.backgroundColor = “red”; to only for first anchor tag.

Explanation of the above code: In this example also we can observe that we have used two anchor tags and inside the anchor tag we have passed the hyperlink of two images. By using the querySelector(“a”).style.backgroundColor = “red”; we have passed the anchor tag (“a”) to the query selector. This time in the querySelector() it will find out the “Desert” hyperlink first as we changed the sequence. Though it contains two anchor tags the first anchor tag which is found, applied its style.backgroundColor = “red”; to only for first anchor tag.

Example #2 – Selecting by class

In this below example we are selecting by using the class name.

Explanation of the above code: In the above example, we are using the class name and here the class name is Selector. The same class name is passed for both h2 (heading tag) and the paragraph tag. For the querySelector() method we are passing the class name it will check for the particular class name in the program. Now it has found those tags which are having the same class name as mentioned. By using the depth-first pre-order traversal of the document the matching of the first element is done. The first element in the example which contains the class name as Selector is h2 (heading tag). The querySelector() method fetches the h2 tag and by style.backgroundColor it applies the particular background color to the h2 tag.

Example #3 – Selecting by ID

In this below example we are selecting by using id.

Explanation of the above code: In the example, we are selecting by using id the id here is Selector. For the querySelector() method we are passing the id it will check for the particular id name in the program. Now it has found the tag which is having the same id name as mentioned. By using the depth-first pre-order traversal of the document the matching of the first element is done. The element in the example which contains the id name as Selector is paragraph tag. The querySelector() method fetches the paragraph tag and applies the particular changes to the content according to the code mentioned.

Uses of jQuery querySelector

Below are the two points explain the uses of querySelector:

The codes of jQuery are more precise, shorter and simpler than the standard JavaScript codes. It can perform a variety of functions.

The call to querySelector() returns the first element as it is picking one, so it is faster and also shorter to write.

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Types And Purpose Of Derivative

Definition of Derivative

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Purpose of Derivatives

The various purpose of entering into derivative contracts is as under:

Earning Profits: The main aim to enter into the derivative contract is to earn profits by doing speculation on the price of an underlying asset in the future. The market price where securities are traded is volatile where the shares may go up or down. When there is a fall in the share price you may suffer loss and in this situation entering into a derivative contract by placing the accurate bet may help in earning gains.

Arbitrage Advantage: Arbitrage trading involves a purchase of security in one market at a low price and then selling the same in the other market at a higher price. The difference between the selling price and the buying price will be the profit of the trader.

To Get Access to Unavailable Markets or Assets: The derivatives help the traders or organizations to get access to the markets or assets that are otherwise not available. For example, interest rate swaps can provide a more favorable rate of interest as compared to the direct borrowings.

Types of Derivatives 1. Futures

Futures are the financial derivatives in which legal agreements are being entered so as to buy or sale a particular derivative stock at the predefined price at the agreed time in the future. Future contracts in order to facilitate its trading over the exchange are standardized. It is the obligation of the buyer to buy the underlying assets upon the expiry of the contract. On the other hand, it is the seller obligation of providing and delivering the underlying asset to the buyer upon expiry of the contract. It allows the investor in speculating in the line of movement of the corresponding underlying stock. It can be used as a tool to hedge the losses which may happen in stock by entering into future agreement long or short depending on the position of stock held. Futures and future contracts refer to the same thing. The contracts are supposed to be compulsorily squared off on or before the expiry date. If anyone wants to continue the same position even after the expiry date, they can roll over the transaction with the new expiry date.

2. Options

The option is a kind of contract that provides a right but not an obligation to purchase/sell an underlying security at a predetermined price (strike price) and during the specified time period. The buyer of the option is required to pay the premium in order to purchase the right from the seller whereas the seller, also known as the option writer, who receives the premium amount, is under the obligation to sell the underlying security if the right is exercised by the buyer. Options are traded on both over counter market and exchange-traded markets. There are two types of options namely call option and put option. The call option is up side betting and no risk for down fall apart from premium paid loss. In the same line put option is down side betting and no risk for upward movement apart from the premium paid loss. The options may be bought or laid depending upon the risk appetite of the investor. If option is bought, it is subjected to maximum risk up to the premium paid amount and the profit bracket is unlimited. If the options are being laid or sold, the maximum profit will be the premium paid amount and is subjected to unlimited risk.

3. Forwards 4. Swaps

A swap is a derivative contract between the two counter parties to exchange the financial instrument or payments or cash flows for a certain time. The underlying instrument to this contract can be anything but in maximum cases, it is involved with cash based on a notional principal amount. Every stream of the cash flow is known as leg. This can be used in hedging the risk and minimizing the uncertainty of certain operations. It is traded over the counter and not in exchange. The default risk in the counter party in the swap contracts is very high and thus it is majorly opted by the financial organizations and the companies. The most popular type of swap includes interest rate swap, currency swap, commodity swap, credit default swap.

Conclusion – Derivative Types

Thus, derivatives are the financial contracts whose value is derived from any underlying asset including stocks, bonds, currencies, market indices etc. the value of underlying asset keeps on changing as per the conditions of the market and the main aim of the derivatives is to make profits by speculating on the value of the given asset in future.

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