Why are some buttons working and some not?

Question

I want to write a simple calculator. However, nothing happens when i click the clear button. I can't understand why this button isn't working, because the function clear() and the function addNumber are almost the same. Here is the HTML.

<!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">
    <title>Calculator</title>
</head>
<body>
    <h1>A simple calculator</h1>
    <span id="num">0</span>
    <hr></hr>
    <button onclick = "symbole('+')">+</button>
    <button onclick="symbole('-')">-</button>
    <button onclick="symbole('*')">*</button>
    <button onclick="symbole('/')">/</button>
    <p></p>
    <button onclick="addNumber(1)">1</button>
    <button onclick="addNumber(2)">2</button>
    <button onclick="addNumber(3)">3</button>
    <p></p>
    <button onclick="addNumber(4)">4</button>
    <button onclick="addNumber(5)">5</button>
    <button onclick="addNumber(6)">6</button>
    <p></p>
    <button onclick="addNumber(7)">7</button>
    <button onclick="addNumber(8)">8</button>
    <button onclick="addNumber(9)">9</button>
    <p></p>
    <button onclick="addNumber(0)">0</button>
    <p></p>
    <button onclick="calculate()">calculate</button>
    <button onclick="backspace()">backspace</button>
    <button onclick="clear()">clear</button>
    <script src="index.js"></script>
</body>
</html>

Here is my JS code.

let num = document.getElementById('num');
let st = undefined;


function addNumber(n){
    if (num.innerText==='0'){
        num.innerText = '';
    }
    num.innerText += n;
}

function symbole(s){
    num.innerText += s;
    st = s;
}



function backspace(){
    num.innerText = num.innerText.split(0,-2);
}
function calculate(){
    let a = 0;
}
function clear(){
    num.innerText = '';
}

Please just ignore calculate(). Can somebody please explain this for me? Thanks! Btw, the backspace button is not working as well.

Why are some buttons working and some not?

0 Answers0