代码示例:(标识:js_number_parsefloat)
<!DOCTYPE html>
<html>
<body>

<h1>JavaScript 数字</h1>

<h2>parseFloat() 方法</h2>

<p>Number.parseFloat() 将字符串转换为数字:</p>

<p id="demo"></p>

<script>
document.getElementById("demo").innerHTML = 
Number.parseFloat("10") + "<br>" +
Number.parseFloat("10.33") + "<br>" +
Number.parseFloat("10 20 30") + "<br>" +
Number.parseFloat("10 years") + "<br>" +
Number.parseFloat("years 10");
</script>

</body>
</html>
运行结果: