To upload an image, use FileReader() in JavaScript. Following is the JavaScript code −Example Live Demo Document    function readImage(fileInput) {       if (fileInput.files && fileInput.files[0]) {          var takingInputFile = new FileReader();          takingInputFile.onload = function(event) {             $('#chooseImage').attr('src', event.target.result);          }          takingInputFile.readAsDataURL(fileInput.files[0]);       }    }    $("#yourImage").change(function() {       readImage(this);    }); To run the above program, save the file name anyName.html(index.html) and right click on the file and select the option Open with live server in VS code editor.Output

The error name value is used for setting or returning the error name. The error name can return the below values.Sl.NoError Name & Description1EvalErrorIt represents an error in the eval() function2RangeErrorIt happens when a numeric value is out of its range3ReferenceErrorIt happens when an illegal reference has occured4SyntaxErrorIt represents a syntax error5TypeErrorIt represents a type error6URIErrorIt represents an error in the encodeURI().ExampleFollowing is the code for the error name values in JavaScript − Live Demo Document    body {       font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;    }    .result {     ... Read More

The try statement allows us execute a block of code and test for errors. Those errors are then caught and handle by the catch statement.Following is the code for try and catch statement in JavaScript −Example Live Demo Document    body {       font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;    }    .result {       font-size: 20px;       font-weight: 500;    } Try and catch in JavaScript CLICK HERE Click on the above button to call a variable before it is defined ... Read More

Following is the code for testing and executing a regular expression in JavaScript −Example Live Demo Document    body {       font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;    }    .result, .sample {       font-size: 20px;       font-weight: 500;    } Testing and executing regular expressions CLICK HERE Click on the above button to test and execute the regular expression    let sampleEle=document.querySelector('.sample');    let resEle = document.querySelector('.result');    let str = 'Hello world. This is a beautiful world';    sampleEle.innerHTML ... Read More

The JavaScript regular expression modifiers are optional part of a regular expression and allow us to perform case insensitive and global searchers. The modifiers can also be combined together.Following are the modifiers −ModifierDescriptiongIt enables global matching and returns all the matched results instead of stopping at first matchiIt enables case insensitive matchingmIt enables multiline matchingExampleFollowing is the code for strict comparison in JavaScript switch statement − Live Demo Document    body {       font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;    }    .result {       font-size: 20px;       font-weight: ... Read More

The JavaScript switch statement only uses strict comparison (===) and doesn’t converts type if matches are not found using strict comparison and will immediately execute the default statement.Following is the code for strict comparison in JavaScript switch statement −Example Live Demo Document    body {       font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;    }    .result {       font-size: 20px;       font-weight: 500;    } JavaScript Switch statement strict comparison Enter day 1-7 CHECK Click on the above button to check if switch ... Read More

Following is the code to implement common code blocks in JavaScript switch statement −Example Live Demo Document    body {       font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;    }    .result {       font-size: 20px;       font-weight: 500;    } JavaScript Switch statement Enter day 1-7 CHECK Click on the above button to check which day it is    let dayVal = document.querySelector(".day");    let resEle = document.querySelector(".result");    document.querySelector(".Btn").addEventListener("click", () => {       switch (parseInt(dayVal.value)) {     ... Read More

The JavaScript Array.isArray() method is used to verify if a JavaScript object is an array or not based on the Boolean value returned by it.Following is the code to verify if JavaScript object is an array −Example Live Demo Document    body {       font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;    }    .result, .sample {       font-size: 20px;       font-weight: 500;    } Verify if a JavaScript object is array CLICK HERE Click on the above button to verify if the above ... Read More

Following is the code to set the day of a date in JavaScript −Example Live Demo Document    body {       font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;    }    .result, .sample {       font-size: 20px;       font-weight: 500;    } Setting day of the date in JavaScript CLICK HERE Click on the above button to change the day of the above date object    let sampleEle = document.querySelector('.sample');    let resEle = document.querySelector(".result");    let dateObj = new Date();   ... Read More

Associative arrays are basically objects in JavaScript where indexes are replaced by user defined keys. They do not have a length property like normal array and cannot be traversed using normal for loop.Following is the code for associative arrays in JavaScript −Example Live Demo Document    body {       font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;    }    .result {       font-size: 20px;       font-weight: 500;    } Associative array in JavaScript CLICK HERE Click on the above button to create a associative array ... Read More