在此页

• 描述
• 静态特性
• 静态方法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

Math is a built-in object that has properties and methods for mathematical constants and functions. It’s not a function object.

Math works with the Number type. It doesn't work with BigInt .

描述

Unlike many other global objects, Math is not a constructor. All properties and methods of Math are static. You refer to the constant pi as Math.PI and you call the sine function as Math.sin( x ) , where x is the method’s argument. Constants are defined with the full precision of real numbers in JavaScript.

注意： Many Math functions have a precision that’s implementation-dependent.

This means that different browsers can give a different result. Even the same JavaScript engine on a different OS or architecture can give different results!

静态特性

Math.E

Euler's constant and the base of natural logarithms; approximately 2.718 .

Math.LN2

Natural logarithm of 2 ; approximately 0.693 .

Math.LN10

Natural logarithm of 10 ; approximately 2.303 .

Math.LOG2E

Base-2 logarithm of E ; approximately 1.443 .

Math.LOG10E

Base-10 logarithm of E ; approximately 0.434 .

Math.PI

Ratio of the a circle's circumference to its diameter; approximately 3.14159 .

Math.SQRT1_2

Square root of ½ (or equivalently, ¹ / _√2 ); approximately 0.707 .

Math.SQRT2

Square root of 2 ; approximately 1.414 .

静态方法

Math.abs( x )

Returns the absolute value of x .

Math.acos( x )

Returns the arccosine of x .

Math.acosh( x )

Returns the hyperbolic arccosine of x .

Math.asin( x )

Returns the arcsine of x .

Math.asinh( x )

Returns the hyperbolic arcsine of a number.

Math.atan( x )

Returns the arctangent of x .

Math.atanh( x )

Returns the hyperbolic arctangent of x .

Math.atan2( y , x )

Returns the arctangent of the quotient of its arguments.

Math.cbrt( x )

Returns the cube root of x .

Math.ceil( x )

Returns the smallest integer greater than or equal to x .

Math.clz32( x )

Returns the number of leading zeroes of the 32-bit integer x .

Math.cos( x )

Returns the cosine of x .

Math.cosh( x )

Returns the hyperbolic cosine of x .

Math.exp( x )

返回 E x , where x is the argument, and E is Euler's constant ( 2.718 …, the base of the natural logarithm).

Math.expm1( x )

Returns subtracting 1 from exp( x ) .

Math.floor( x )

Returns the largest integer less than or equal to x .

Math.fround( x )

Returns the nearest single precision float representation of x .

Math.hypot([ x [, y [, …]]])

Returns the square root of the sum of squares of its arguments.

Math.imul( x , y )

Returns the result of the 32-bit integer multiplication of x and y .

Math.log( x )

Returns the natural logarithm (㏒ _e ; also, ㏑) of x .

Math.log1p( x )

Returns the natural logarithm (㏒ _e ; also ㏑) of 1 + x for the number x .

Math.log10( x )

Returns the base-10 logarithm of x .

Math.log2( x )

Returns the base-2 logarithm of x .

Math.max([ x [, y [, …]]])

Returns the largest of zero or more numbers.

Math.min([ x [, y [, …]]])

Returns the smallest of zero or more numbers.

Math.pow( x , y )

Returns base x to the exponent power y (that is, x y ).

Math.random()

Returns a pseudo-random number between 0 and 1 .

Math.round( x )

Returns the value of the number x rounded to the nearest integer.

Math.sign( x )

Returns the sign of the x , indicating whether x is positive, negative, or zero.

Math.sin( x )

Returns the sine of x .

Math.sinh( x )

Returns the hyperbolic sine of x .

Math.sqrt( x )

Returns the positive square root of x .

Math.tan( x )

Returns the tangent of x .

Math.tanh( x )

Returns the hyperbolic tangent of x .

Math.trunc( x )

Returns the integer portion of x , removing any fractional digits.

范例

在角度和弧度之间转换

The trigonometric functions sin() , cos() , tan() , asin() , acos() , atan() ，和 atan2() expect (and return) angles in radians .

Since humans tend to think in degrees, and some functions (such as CSS transforms) can accept degrees, it is a good idea to keep functions handy that convert between the two:

function degToRad(degrees) {
  return degrees * (Math.PI / 180);
};
function radToDeg(rad) {
  return rad / (Math.PI / 180);
};
					

计算等边三角形的高度

If we want to calculate the height of an equalateral triangle, and we know its side length is 100, we can use the formulae length of the adjacent multiplied by the tangent of the angle is equal to the opposite.

In JavaScript, we can do this with the following:

50 * Math.tan(degToRad(60)).
					

We use our degToRad() function to convert 60 degrees to radians, as Math.tan() expects an input value in radians.

返回 2 边界之间的随机整数

This can be achieved with a combination of Math.random() and Math.floor() :

function random(min, max) {
  const num = Math.floor(Math.random() * (max - min + 1)) + min;
  return num;
}
random(1, 10);
					

规范

规范
ECMAScript (ECMA-262) The definition of 'Math' 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
E	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
LN2	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
LN10	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
LOG2E	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
LOG10E	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
PI	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
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
SQRT2	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
abs	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
acos	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
acosh	Chrome 38	Edge 12	Firefox 25	IE No	Opera 25	Safari 8	WebView Android 38	Chrome Android 38	Firefox Android 25	Opera Android 25	Safari iOS 8	Samsung Internet Android 3.0	nodejs 0.12
asin	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
asinh	Chrome 38	Edge 12	Firefox 25	IE No	Opera 25	Safari 8	WebView Android 38	Chrome Android 38	Firefox Android 25	Opera Android 25	Safari iOS 8	Samsung Internet Android 3.0	nodejs 0.12
atan	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
atan2	Chrome 1	Edge 12	Firefox 1	IE 4	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
atanh	Chrome 38	Edge 12	Firefox 25	IE No	Opera 25	Safari 8	WebView Android 38	Chrome Android 38	Firefox Android 25	Opera Android 25	Safari iOS 8	Samsung Internet Android 3.0	nodejs 0.12
cbrt	Chrome 38	Edge 12	Firefox 25	IE No	Opera 25	Safari 8	WebView Android 38	Chrome Android 38	Firefox Android 25	Opera Android 25	Safari iOS 8	Samsung Internet Android 3.0	nodejs 0.12
ceil	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
clz32	Chrome 38	Edge 12	Firefox 31	IE No	Opera 25	Safari 7	WebView Android 38	Chrome Android 38	Firefox Android 31	Opera Android 25	Safari iOS 7	Samsung Internet Android 3.0	nodejs 0.12
cos	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
cosh	Chrome 38	Edge 12	Firefox 25	IE No	Opera 25	Safari 8	WebView Android 38	Chrome Android 38	Firefox Android 25	Opera Android 25	Safari iOS 8	Samsung Internet Android 3.0	nodejs 0.12
exp	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
expm1	Chrome 38	Edge 12	Firefox 25	IE No	Opera 25	Safari 8	WebView Android 38	Chrome Android 38	Firefox Android 25	Opera Android 25	Safari iOS 8	Samsung Internet Android 3.0	nodejs 0.12
floor	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
fround	Chrome 38	Edge 12	Firefox 26	IE No	Opera 25	Safari 8	WebView Android 38	Chrome Android 38	Firefox Android 26	Opera Android 25	Safari iOS 8	Samsung Internet Android 3.0	nodejs 0.12
hypot	Chrome 38	Edge 12	Firefox 27	IE No	Opera 25	Safari 8	WebView Android 38	Chrome Android 38	Firefox Android 27	Opera Android 25	Safari iOS 8	Samsung Internet Android 3.0	nodejs 0.12
imul	Chrome 28	Edge 12	Firefox 20	IE No	Opera 16	Safari 7	WebView Android ≤37	Chrome Android 28	Firefox Android 20	Opera Android 15	Safari iOS 7	Samsung Internet Android 1.5	nodejs 0.12
log	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
log1p	Chrome 38	Edge 12	Firefox 25	IE No	Opera 25	Safari 8	WebView Android 38	Chrome Android 38	Firefox Android 25	Opera Android 25	Safari iOS 8	Samsung Internet Android 3.0	nodejs 0.12
log2	Chrome 38	Edge 12	Firefox 25	IE No	Opera 25	Safari 8	WebView Android 38	Chrome Android 38	Firefox Android 25	Opera Android 25	Safari iOS 8	Samsung Internet Android 3.0	nodejs 0.12
log10	Chrome 38	Edge 12	Firefox 25	IE No	Opera 25	Safari 8	WebView Android 38	Chrome Android 38	Firefox Android 25	Opera Android 25	Safari iOS 8	Samsung Internet Android 3.0	nodejs 0.12
max	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
min	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
pow	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
random	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
round	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
sign	Chrome 38	Edge 12	Firefox 25	IE No	Opera 25	Safari 9	WebView Android 38	Chrome Android 38	Firefox Android 25	Opera Android 25	Safari iOS 9	Samsung Internet Android 3.0	nodejs 0.12
sin	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
sinh	Chrome 38	Edge 12	Firefox 25	IE No	Opera 25	Safari 8	WebView Android 38	Chrome Android 38	Firefox Android 25	Opera Android 25	Safari iOS 8	Samsung Internet Android 3.0	nodejs 0.12
sqrt	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
tan	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
tanh	Chrome 38	Edge 12	Firefox 25	IE No	Opera 25	Safari 8	WebView Android 38	Chrome Android 38	Firefox Android 25	Opera Android 25	Safari iOS 8	Samsung Internet Android 3.0	nodejs 0.12
trunc	Chrome 38	Edge 12	Firefox 25	IE No	Opera 25	Safari 8	WebView Android 38	Chrome Android 38	Firefox Android 25	Opera Android 25	Safari iOS 8	Samsung Internet Android 3.0	nodejs 0.12

图例

完整支持

完整支持

不支持

不支持

另请参阅

• Number

元数据

• 最后修改： Jun 7, 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()