Math.sign()

Summary

The Math.sign() function returns the sign of a number, indicating whether the number is positive, negative or zero.

Syntax

Math.sign(x)

Parameters

x

A number.

Description

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

This function has 5 kinds of return values, 1, -1, 0, -0, NaN, which represent "positive number", "negative number", "positive zero",  "negative zero" and NaN respectively.

The argument passed to this function will be converted to number type implicitly.

Examples

Example: Using Math.sign

Math.sign(3)     //  1
Math.sign(-3)    // -1
Math.sign("-3")  // -1
Math.sign(0)     //  0
Math.sign(-0)    // -0
Math.sign(NaN)   // NaN
Math.sign("foo") // NaN
Math.sign()      // NaN

Specifications

Browser compatibility

See also

• The Math object it belongs to.