Math.sqrt()

Math.sqrt() 静态方法返回数字的平方根。那是

¥The Math.sqrt() static method returns the square root of a number. That is

x 0 , 𝙼𝚊𝚝𝚑.𝚜𝚚𝚛𝚝 ( 𝚡 ) = x = the unique  y 0  such that  y 2 = x \forall x \geq 0,;\mathtt{\operatorname{Math.sqrt}(x)} = \sqrt{x} = \text{the unique } y \geq 0 \text{ such that } y^2 = x

Try it

语法

¥Syntax

js
Math.sqrt(x)

参数

¥Parameters

x

大于或等于 0 的数字。

返回值

¥Return value

x 的平方根,一个非负数。如果是 x < 0,则返回 NaN

¥The square root of x, a nonnegative number. If x < 0, returns NaN.

描述

¥Description

因为 sqrt()Math 的静态方法,所以你始终将其用作 Math.sqrt(),而不是用作你创建的 Math 对象的方法(Math 不是构造函数)。

¥Because sqrt() is a static method of Math, you always use it as Math.sqrt(), rather than as a method of a Math object you created (Math is not a constructor).

示例

¥Examples

使用 Math.sqrt()

¥Using Math.sqrt()

js
Math.sqrt(-1); // NaN
Math.sqrt(-0); // -0
Math.sqrt(0); // 0
Math.sqrt(1); // 1
Math.sqrt(2); // 1.414213562373095
Math.sqrt(9); // 3
Math.sqrt(Infinity); // Infinity

规范

Specification
ECMAScript Language Specification
# sec-math.sqrt

¥Specifications

浏览器兼容性

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¥Browser compatibility

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