La funciónMath.log() devuelve la base neutral de un número (basee)

La función en JavaScrcripMath.log() es equivalente aln(x) en matematicas.

Pruébalo

function getBaseLog(x, y) {  return Math.log(y) / Math.log(x);}// 2 x 2 x 2 = 8console.log(getBaseLog(2, 8));// Expected output: 3// 5 x 5 x 5 x 5 = 625console.log(getBaseLog(5, 625));// Expected output: 4

Sintaxis

Math.log(x)

Parametetros

x

Es un numero.

Retorna el valor

La base natural (basee) del número dado. Si el número es negativo, se devuelveNaN

Descripcion

If the value ofx is negative, the return value is alwaysNaN.

Becauselog() is a static method ofMath, you always use it asMath.log(), rather than as a method of aMath object you created (Math is not a constructor).

If you need the natural log of 2 or 10, use the constantsMath.LN2 orMath.LN10 . If you need a logarithm to base 2 or 10, useMath.log2() orMath.log10() . If you need a logarithm to other bases, use Math.log(x) / Math.log(otherBase) as in the example below; you might want to precalculate 1 / Math.log(otherBase) .

Examples

UsingMath.log()

Math.log(-1); // NaN, out of rangeMath.log(0); // -InfinityMath.log(1); // 0Math.log(10); // 2.302585092994046

UsingMath.log() with a different base

The following function returns the logarithm ofy with basex (ie.${log}_{x}y$):

function getBaseLog(x, y) {  return Math.log(y) / Math.log(x);}

If you rungetBaseLog(10, 1000) it returns2.9999999999999996 due to floating-point rounding, which is very close to the actual answer of 3.

Especificaciones

Compatibilidad con navegadores

See also

• Math.exp()
• Math.log1p()
• Math.log10()
• Math.log2()
• Math.pow()