p5.js displayWidth Variable

The displayWidth variable in p5.js is used to store the width of the screen display of the device and it is according to The default pixelDensity. This variable is used to run a full-screen program on any display size. Multiply this by pixelDensity to return actual screen size.

Syntax:

displayWidth()

Parameters: This function does not accept any parameter.

Below program illustrates the displayWidth variable in p5.js:
Example-1:

function setup() {

    // use of displayWidth variable
    createCanvas(displayWidth, 400);

    // Set text size to 40px
    textSize(20);
}

function draw() {

    background(200);
    rect(mouseX, mouseY, 30, 30);

    //Use of windowWidth Variable
    text("Display Width is " + windowWidth, 30, 40);
}

Output:

Example-2:

function setup() {

    // use of displayWidth variable
    createCanvas(displayWidth, displayHeight);

    // Set text size to 40px
    textSize(20);
}

function draw() {
    background(200);
    rect(mouseX, mouseY, 30, 30);

    //Use of windowWidth Variable
    text("Canvas Display Height is " + displayHeight, 30, 40);
}

Output:

Reference: https://p5js.org/reference/#/p5/displayWidth