Math.SQRT1_2
Math.SQRT1_2
Math.SQRT1_2
属性表示 1/2 的平方根,约为 0.707:
Math.SQRT1_2=12=12≈0.707\mathtt{\mi{Math.SQRT1_2}} = \sqrt{\frac{1}{2}} = \frac{1}{\sqrt{2}} \approx 0.707
| Math.SQRT1_2
属性的属性特性 |
|:----|
| Writable | no |
| Enumerable | no |
| Configurable | no |
描述
由于SQRT1_2
是Math
对象的静态属性,所以应该像这样使用:Math.SQRT1_2
,而不是作为你创建的 Math
实例的属性(Math
不是构造函数)。
示例
使用Math.SQRT1_2
下面的函数返回 1/2 的平方根:
function getRoot1_2() {
return Math.SQRT1_2;
}
getRoot1_2( // 0.7071067811865476
规范
Specification | Status | Comment |
---|---|---|
ECMAScript 1st Edition (ECMA-262) | Standard | Initial definition. Implemented in JavaScript 1.0. |
ECMAScript 5.1 (ECMA-262)The definition of 'Math.SQRT1_2' in that specification. | Standard | |
ECMAScript 2015 (6th Edition, ECMA-262)The definition of 'Math.SQRT1_2' in that specification. | Standard | |
ECMAScript Latest Draft (ECMA-262)The definition of 'Math.SQRT1_2' in that specification. | Draft | |
浏览器兼容性
Feature | Chrome | Firefox | Edge | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|---|
Basic Support | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) |
Feature | Android | Chrome for Android | Edge mobile | Firefox for Android | IE mobile | Opera Android | iOS Safari |
---|---|---|---|---|---|---|---|
Basic Support | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) |