The Math.expm1()
function returns ex - 1
, where x
is the argument, and e the base of the natural logarithms.
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Syntax
Math.expm1(x)
Parameters
x
- A number.
Return value
A number representing ex - 1
, where e
is Euler's number and x
is the argument.
Description
Because expm1()
is a static method of Math
, you always use it as Math.expm1()
, rather than as a method of a Math
object you created (Math
is not a constructor).
Polyfill
This can be emulated with the help of the Math.exp()
function:
Math.expm1 = Math.expm1 || function(x) { return Math.exp(x) - 1; };
Examples
Using Math.expm1()
Math.expm1(-1); // -0.6321205588285577 Math.expm1(0); // 0 Math.expm1(1); // 1.718281828459045
Specifications
Specification |
---|
ECMAScript (ECMA-262) The definition of 'Math.expm1' in that specification. |
Browser compatibility
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.
Desktop | Mobile | Server | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
expm1 | Chrome Full support 38 | Edge Full support 12 | Firefox Full support 25 | IE No support No | Opera Full support 25 | Safari Full support 8 | WebView Android Full support 38 | Chrome Android Full support 38 | Firefox Android Full support 25 | Opera Android Full support 25 | Safari iOS Full support 8 | Samsung Internet Android Full support 3.0 | nodejs Full support 0.12 |
Legend
- Full support
- Full support
- No support
- No support