A JavaScript function is defined with the function keyword, followed by a name, followed by parentheses (). Function names can contain letters, digits, underscores, and dollar signs (same rules as variables).

Sep 30, 2012 · We can modify a DOM element and add to its prototype. For example, if we want to add something only to the canvas, we'd do something like this: HTMLCanvasElement.prototype.doSomething = function(arg) { ... }; We can then perform this action on a canvas element: var canvas = document.getElementById('canvasId'); canvas.doSomething(...);

Sep 7, 2017 · You should pass the html element to your javascript function. Add an element argument in your function definition. function divFunction(el){ alert(el.innerHTML); } And use getElementById to reference the element to use as an argument. <div id="example">Hello!</div> <script> divFunction(document.getElementById("example")); </script>

Nov 2, 2009 · You can do this because JavaScript functions are first-class objects. Edit: If your function receives arguments, you should use apply to pass them to the original function : addToMe = function () { originalFn.apply(this, arguments); // preserve the arguments // other stuff };

Apr 15, 2025 · Functions in JavaScript are reusable blocks of code designed to perform specific tasks. They allow you to organize, reuse, and modularize code. It can take inputs, perform actions, and return outputs. A function definition is sometimes also termed a function declaration or function statement.

Jan 10, 2025 · To add JavaScript in HTML document, several methods can be used. These methods include embedding JavaScript directly within the HTML file or linking an external JavaScript file. You can write JavaScript code directly inside the HTML element using the onclick, onmouseover, or other event handler attributes. Click Here. </button>

The add() method inserts a new element in the set. Required. The value to add. A set object with the added value. set.add() is an ECMAScript6 (ES6) feature. ES6 (JavaScript 2015) is supported in all modern browsers since June 2017: set.add() is not supported in Internet Explorer.

Mar 22, 2025 · In JavaScript, a function can be defined based on a condition. For example, the following function definition defines myFunc only if num equals 0: theObject.make = "Toyota"; }; } In addition to defining functions as described here, you can also use the Function constructor to create functions from a string at runtime, much like eval().

JavaScript provides many built-in functions such as parseInt() and parseFloat(). In this tutorial, you will learn how to develop custom functions. To declare a function, you use the function keyword, followed by the function name, a list of parameters, and the function body as follows: // function body // ...

We can create a function in JavaScript using the function keyword: console.log("Hello World!"); Here, we have created a simple function named greet() that prints Hello World! on the screen. Our function contains the following parts: Function Keyword - The …