HTML5實現科學計數器源代碼示例：
<!DOCTYPE html>
<html>
<head>
<title>科學計數器</title>
<meta charset="utf-8">
</head>
<body>
<input id="display" type="text"/>
<br/>
<button onclick="del()">del</button>
<button onclick="num('7')">7</button>
<button onclick="num('8')">8</button>
<button onclick="num('9')">9</button>
<button onclick="op('+')">+</button>
<br/>
<button onclick="num('4')">4</button>
<button onclick="num('5')">5</button>
<button onclick="num('6')">6</button>
<button onclick="op('-')">-</button>
<br/>
<button onclick="num('1')">1</button>
<button onclick="num('2')">2</button>
<button onclick="num('3')">3</button>
<button onclick="op('*')">*</button>
<br/>
<button onclick="clearScreen()">clear</button>
<button onclick="num('0')">0</button>
<button onclick="dot()">.</button>
<button onclick="op('/')">/</button>
<br/>
<button onclick="equal()">=</button>
</body>
<script>
var num1 = 0;
var num2 = 0;
var operator = '';
var result = 0;
function num(num) {
document.getElementById("display").value += num;
}
function op(op) {
num1 = parseFloat(document.getElementById("display").value);
operator = op;
document.getElementById("display").value = '';
}
function equal() {
num2 = parseFloat(document.getElementById("display").value);
switch (operator) {
case '+':
result = num1 + num2;
break;
case '-':
result = num1 - num2;
break;
case '*':
result = num1 * num2;
break;
case '/':
result = num1 / num2;
break;
}
document.getElementById("display").value = result.toString();
}
function dot() {
if (document.getElementById("display").value.indexOf(".") == -1) {
document.getElementById("display").value += '.';
}
}
function del() {
var str = document.getElementById("display").value;
document.getElementById("display").value = str.substring(0, str.length - 1);
}
function clearScreen() {
document.getElementById("display").value = '';
}
</script>
</html>