Math.SQRT1_2

概述

Math.SQRT1_2 属性表示 1/2 的平方根,约为 0.707:

Math.SQRT1_2 = 1 2 = 1 2 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 false
enumerable false
configurable false

描述

由于 SQRT1_2Math 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

例子:使用 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

规范版本 规范状态 注解
ECMAScript 1st Edition. Implemented in JavaScript 1.0 Standard Initial definition.
ECMAScript 5.1 (ECMA-262)
Math.SQRT1_2
Standard  
ECMAScript 2015 (6th Edition, ECMA-262)
Math.SQRT1_2
Standard  

浏览器兼容性

We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support (Yes) (Yes) (Yes) (Yes) (Yes)
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support (Yes) (Yes) (Yes) (Yes) (Yes) (Yes)

相关链接

  • The Math object it belongs to.