The object.is() method introduced in ES6 as a way to compare two values. These two values can either be primitives or objects. It does a little better comparison than == and ===.Following is the code for object.is() in equality comparison −Example Live Demo Document    body {       font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;    }    .result {       font-size: 18px;       font-weight: 500;       color: blueviolet;    } Object.is() equality comparsion Click here Click on the above button to compare objects ... Read More

Event Bubbling − Whenever an event happens on an element, the event handlers will first run on it and then on its parent and finally all the way up to its other ancestors.Event Capturing − It is the reverse of the event bubbling and here the event starts from the parent element and then to its child element.Following is the code for event bubbling vs event capturing in JavaScript −Example Live Demo Document    body {       font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;    }    .result {       font-size: 18px; ... Read More

The JavaScript undefined property specifies if a variable has been declared or assigned a value yet.Following is the code implementing the JavaScript undefined property −Example Live Demo Document    body {       font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;    }    .sample {       font-size: 18px;       font-weight: 500;       color: red;    } JavaScript undefined property CLICK HERE CLICK the above button to know if variable age has been defined or not    let sampleEle = document.querySelector(".sample");    let age;   ... Read More

Template were introduced in ES6 to allow embed expressions inside a string. Instead of ‘’ or “” quotation marks they use the backticks (``). They offer a much better way of string interpolation and expressions can be embedded in a way like ${a+b}. It offers a much nicer syntax than the + operator.Following is the code for template strings in JavaScript −Example Live Demo Document    body {       font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;    }    .result {       font-size: 20px;       font-weight: 500;       ... Read More

Escape characters are characters that can be interpreted in some alternate way then what we intended to. To print these characters as it is, include backslash ‘\’ in front of them. Following are the escape characters in JavaScript −CodeResult\bBackspace\fForm FeedNew Line\rCarriage Return\tHorizontal Tabulator\vVertical Tabulator\'Single quote\"Double quote\BackslashFollowing is the code implement escape character Backslash in javaScript −Example Live Demo Document    body {       font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;    }    .result {       font-size: 18px;       font-weight: 500;    } Escape characters in JavaScript ... Read More

The Set data type was introduced in ES2015 and the difference between array and set is that while an array can have duplicate values a set can’t. Elements can be accessed in array using index which isn’t possible in Set since it uses keys and elements can be traversed only in the way they were entered.Following is the code displaying the difference between array and Set in JavaScript −Example Live Demo Document    body {       font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;    }    .result, .sample {       font-size: 18px; ... Read More

Following is the code to pass JavaScript primitive and object types to function −Example Live Demo Document    body {       font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;    }    .result {       font-size: 18px;       font-weight: 500;       color: blueviolet;    } Passing primitive/object types to function Click here Click on the above button to pass primitive and object to a function and call it    let BtnEle = document.querySelector(".Btn");    let resEle = document.querySelector(".result");    let person = { ... Read More

innerHTML − The innerHTML property returns the text, including all spacing and inner element tags. It preserves the formatting of the text and all the extra tags like , etc.innerText − The innerText property returns just the text, removing the spacing and the inner element tags.Following is the code for innerHTML and innerText in JavaScript −Example Live Demo Document    body {       font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;    }    .result,    .sample {       font-size: 18px;       font-weight: 500;       color: red;   ... Read More

Undeclared − It occurs when a variable which hasn’t been declared using var, let or const is being tried to access.Undefined − It occurs when a variable has been declared using var, let or const but isn’t given a value.Following is the code for undeclared and undefined in JavaScript −Example Live Demo Document    body {       font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;    }    .result {       font-size: 18px;       font-weight: 500;       color: blueviolet;    } Undeclared vs Undefined ... Read More

Following is the code for validating a file size in JavaScript while uploading −Example Live Demo Document    body {       font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;    }    .result {       font-size: 18px;       font-weight: 500;       color: blueviolet;    } Validating a file size while uploading Upload a file using the above file input type    let BtnEle = document.querySelector(".Btn");    let resEle = document.querySelector(".result");    let fileEle = document.querySelector(".file");    function validateFile() {       if ... Read More