The hasClass() method of p5.Element in p5.js is used to check if the specified class is already present in the element. It returns a boolean value denoting if the class was present or not. An element can have multiple classes assigned to it.
Syntax:
hasClass( class )
Parameters: This function accepts a single parameter as mentioned above and described below.
- class: It is a string that denotes the class to be checked.
Example: The example below illustrates the hasClass() method in p5.js
< html > < head > < script src = </ script > < script src = "sketch.js" ></ script > </ head > < body ></ body > </ html > |
Javascript code: The following code is used for the above “sketch.js” file.
Javascript
function setup() { createCanvas(600, 300); textSize(18); // Create a new p5.Element tmpElement = createElement( "div" ); text( "Click on the buttons to add, remove " + "or check the class of the element" , 20, 20); setBtn = createButton( "Add color class to element" ); setBtn.position(30, 40); setBtn.mouseClicked(() => { tmpElement.addClass( "color" ); }); removeBtn = createButton( "Remove color class from element" ); removeBtn.position(30, 80); removeBtn.mouseClicked(() => { tmpElement.removeClass( "color" ); }); showBtn = createButton( "Check if class exists" ); showBtn.position(30, 120); showBtn.mouseClicked(checkClass); } function checkClass() { clear(); // Check if the given class exists let hasC = tmpElement.hasClass( "color" ); text( "hasClass('color') gives the output: " + hasC, 20, 180); text( "Click on the buttons to add, remove or " + "check the class of the element" , 20, 20); } |
Output:
Online editor: https://editor.p5js.org/
Environment Setup: https://www.geeksforgeeks.org/p5-js-soundfile-object-installation-and-methods/
Reference: https://p5js.org/reference/#/p5.Element/hasClass