Math.log()
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
La función Math.log()
devuelve la base neutral de un número (base e
)
La función en JavaScrcrip Math.log()
es equivalente a ln(x) en matematicas.
Pruébalo
Sintaxis
Math.log(x)
Parametetros
x
-
Es un numero.
Retorna el valor
Descripcion
If the value of x
is negative, the return value is always NaN
.
Because log()
is a static method of Math
, you always use it as Math.log()
, rather than as a method of a Math
object you created (Math
is not a constructor).
If you need the natural log of 2 or 10, use the constants Math.LN2
or Math.LN10
. If you need a logarithm to base 2 or 10, use Math.log2()
or Math.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
Using Math.log()
Math.log(-1); // NaN, out of range
Math.log(0); // -Infinity
Math.log(1); // 0
Math.log(10); // 2.302585092994046
Using Math.log()
with a different base
The following function returns the logarithm of y
with base x
(ie.
):
function getBaseLog(x, y) {
return Math.log(y) / Math.log(x);
}
If you run getBaseLog(10, 1000)
it returns 2.9999999999999996
due to floating-point rounding, which is very close to the actual answer of 3.
Especificaciones
Specification |
---|
ECMAScript Language Specification # sec-math.log |
Compatibilidad con navegadores
BCD tables only load in the browser