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Version: 3.13.0

Math.log()

The Math.log() function returns the natural logarithm (base E) of a number.

Syntax​

Math.log(x)

Parameters​

  • x
    • : A number greater than or equal to 0.

Return value​

The natural logarithm (base E) of x. If x is ±0, returns -Infinity. If x < 0, returns NaN.

Description​

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) since multiplication in Math.log(x) * constant is much faster.

Beware that positive numbers very close to 1 can suffer from loss of precision and make its natural logarithm less accurate. In this case, you may want to use Math.log1p instead.