How to keep a random occurring botton inside the body(Or inside any div)

January 2, 2022

I Made a button using html, css and js which occurs randomly on the page.But i want the button inside the body tag and it keeps getting out.

HTML CODE:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <script src="main.js" defer></script>
    <link rel="stylesheet" href="style.css">
    <title>SReflex</title>
</head>
<body>
    <button class="random">1 </button>
    
    
</body>
</html>

CSS CODE:

*{
    margin:0%;
    padding:0%;
}

body{
    height: 100vh;
    width: 100vw;
    position: fixed;

}

button.random {

    /* looks of the button */
    height: 3rem;
    width: 3rem;
    border: black;
    border-style: solid;
    border-radius: 50%;

  
    display:block;
    position:absolute;
}

JS CODE:

let temp= document.querySelector(".random");
temp.addEventListener("click",change);

function change(){
    let posx = Math.floor(Math.random()*1000);
    let posy = Math.floor(Math.random()*1000);
    let posz = Math.floor(Math.random()*1000);
    temp.style.left= posx + "vw";
    temp.style.top= posy+ "vh";
    temp.style.right= posz+ "vw";
}

How do i make the button to not go off screen, i want the page to not include the scroll bar.

>Solution :

Here is an easy way to do so, it works for the body or for a containing div because it’s related to parent size.
check out the snippet.

let temp= document.querySelector(".random");
temp.addEventListener("click",change);
let maxw = temp.parentElement.clientWidth - 50;
let maxh = temp.parentElement.clientHeight - 50;
function change(){
    let posx = Math.floor(Math.random() * (maxw));
    let posy = Math.floor(Math.random() * (maxh))
    temp.style.left= posx + "px";
    temp.style.top= posy+ "px";
}

*{
    margin:0%;
    padding:0%;
}

body{
    height: 100vh;
    width: 100vw;
    position: fixed;

}

button.random {

    /* looks of the button */
    height: 3rem;
    width: 3rem;
    border: black;
    border-style: solid;
    border-radius: 50%;

  
    display:block;
    position:absolute;
}

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <script src="main.js" defer></script>
    <link rel="stylesheet" href="style.css">
    <title>SReflex</title>
</head>
<body>
    <button class="random">1 </button>
    
    
</body>
</html>

the -50 is to make sure it doesn’t cross the edges, you can edit that to suit your needs.