javascript-basics/arithmetic.html at main · DEMiHAT/javascript-basics · GitHub

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<!DOCTYPE html>
<html>
<head>
    <title>Basic Arithmetic Operations</title>
</head>
<body>

<h2>Basic Arithmetic Operations</h2>

<form>
    <label>Enter first number:</label><br>
    <input type="number" id="num1" placeholder="Enter number 1"><br><br>

    <label>Enter second number:</label><br>
    <input type="number" id="num2" placeholder="Enter number 2"><br><br>

    <input type="button" value="Add (+)" onclick="calculate('add')">
    <input type="button" value="Subtract (–)" onclick="calculate('sub')">
    <input type="button" value="Multiply (×)" onclick="calculate('mul')">
    <input type="button" value="Divide (÷)" onclick="calculate('div')">
</form>

<p id="result"></p>

<script>
    function add(a, b) {
        return a + b;
    }

    function subtract(a, b) {
        return a - b;
    }

    function multiply(a, b) {
        return a * b;
    }

    function divide(a, b) {
        if (b === 0) {
            return "Division by zero is not allowed.";
        }
        return a / b;
    }

    function calculate(operation) {
        let a = parseFloat(document.getElementById("num1").value);
        let b = parseFloat(document.getElementById("num2").value);

        if (isNaN(a) || isNaN(b)) {
            document.getElementById("result").innerHTML = "Please enter valid numbers.";
            return;
        }

        let result;

        switch (operation) {
            case 'add': result = add(a, b); break;
            case 'sub': result = subtract(a, b); break;
            case 'mul': result = multiply(a, b); break;
            case 'div': result = divide(a, b); break;
        }

        document.getElementById("result").innerHTML = "Result: " + result;
    }
</script>

</body>
</html>