在此页

• 描述
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

Math.SQRT1_2 property represents the square root of 1/2 which is approximately 0.707:

$$\mathtt{\mi{Math.SQRT1_2}} = \sqrt{\frac{1}{2}} = \frac{1}{\sqrt{2}} \approx 0.707$$

The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.

特性属性在 Math.SQRT1_2
可写	no
可枚举	no
可配置	no

描述

因为 SQRT1_2 is a static property of Math , you always use it as Math.SQRT1_2 , rather than as a property of a Math object you created ( Math is not a constructor).

范例

使用 Math.SQRT1_2

The following function returns 1 over the square root of 2:

function getRoot1_2() {
  return Math.SQRT1_2;
}
getRoot1_2(); // 0.7071067811865476
					

规范

规范
ECMAScript (ECMA-262) The definition of 'Math.SQRT1_2' in that specification.

浏览器兼容性

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

更新 GitHub 上的兼容性数据

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
SQRT1_2	Chrome 1	Edge 12	Firefox 1	IE 3	Opera 3	Safari 1	WebView Android 1	Chrome Android 18	Firefox Android 4	Opera Android 10.1	Safari iOS 1	Samsung Internet Android 1.0	nodejs 0.1.100

图例

完整支持

完整支持

另请参阅

• Math.pow()
• Math.sqrt()

元数据

• 最后修改： Mar 4, 2020

相关话题

1. 标准内置对象
2. Math
3. 特性
   1. Math.E
   2. Math.LN10
   3. Math.LN2
   4. Math.LOG10E
   5. Math.LOG2E
   6. Math.PI
   7. Math.SQRT1_2
   8. Math.SQRT2
4. 方法
   1. Math.abs()
   2. Math.acos()
   3. Math.acosh()
   4. Math.asin()
   5. Math.asinh()
   6. Math.atan()
   7. Math.atan2()
   8. Math.atanh()
   9. Math.cbrt()
   10. Math.ceil()
   11. Math.clz32()
   12. Math.cos()
   13. Math.cosh()
   14. Math.exp()
   15. Math.expm1()
   16. Math.floor()
   17. Math.fround()
   18. Math.hypot()
   19. Math.imul()
   20. Math.log()
   21. Math.log10()
   22. Math.log1p()
   23. Math.log2()
   24. Math.max()
   25. Math.min()
   26. Math.pow()
   27. Math.random()
   28. Math.round()
   29. Math.sign()
   30. Math.sin()
   31. Math.sinh()
   32. Math.sqrt()
   33. Math.tan()
   34. Math.tanh()
   35. Math.trunc()
5. 继承：
6. Object
7. 特性
   1. Object.prototype.__proto__
   2. Object.prototype.constructor
8. 方法
   1. Object.prototype.__defineGetter__()
   2. Object.prototype.__defineSetter__()
   3. Object.prototype.__lookupGetter__()
   4. Object.prototype.__lookupSetter__()
   5. Object.prototype.hasOwnProperty()
   6. Object.prototype.isPrototypeOf()
   7. Object.prototype.propertyIsEnumerable()
   8. Object.prototype.toLocaleString()
   9. Object.prototype.toSource()
   10. Object.prototype.toString()
   11. Object.prototype.valueOf()
   12. Object.setPrototypeOf()