Number.parseFloat()
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
Number.parseFloat()
静态方法解析参数并返回浮点数。如果无法从参数中解析出一个数字,则返回 NaN
。
尝试一下
function circumference(r) {
if (Number.isNaN(Number.parseFloat(r))) {
return 0;
}
return parseFloat(r) * 2.0 * Math.PI;
}
console.log(circumference("4.567abcdefgh"));
// Expected output: 28.695307297889173
console.log(circumference("abcdefgh"));
// Expected output: 0
语法
js
Number.parseFloat(string)
参数
返回值
由给定 string
解析得到的浮点数。
如果第一个非空白字符不能被转换为数字,则返回 NaN
。
示例
Number.parseFloat 与 parseFloat 对比
此方法与全局函数 parseFloat()
具有相同的功能:
js
Number.parseFloat === parseFloat; // true
其目的是全局的模块化。
有关更多详细信息和示例,请参见 parseFloat()
。
规范
Specification |
---|
ECMAScript® 2025 Language Specification # sec-number.parsefloat |
浏览器兼容性
Report problems with this compatibility data on GitHubdesktop | mobile | server | ||||||||||||
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parseFloat |
Legend
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- Full support
- Full support
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