калькулятор2

by Axelvaisper

HTML

<body onload="timer()">
<h1>Калькулятор</h1>
<form>
<input type="textarea" name="firstNumber">
<select name="operations" size="1">
        <option value="+">+</option>
        <option value="-">-</option>
        <option value="*">*</option>
        <option value="/">/</option>
<input type="textarea" name="secondNumber">
<input type="button" onclick="Calculate()" value="Результат"><br>
</select>
</form>
</body>

JavaScript

function Calculate()
{
        var a = parseFloat(document.forms[0].firstNumber.value);
        var b = parseFloat(document.forms[0].secondNumber.value);
        var op = document.forms[0].operations.options[document.forms[0].operations.selectedIndex].value;
        var res;
        switch (op)
        {
        case "+":
                res = a + b;
                break;
        case "-":
                res = a - b;
                break;
        case "*":
                res = a * b;
                break;
        case "/":
                if(b==0)
                {
                        alert("Деление на ноль!");
                        return;
                }
                res = a / b;
                break;
        }
        alert("Результат: " + res);
}