JavaScript Math log2()

The JavaScript Math.log2() function returns the base 2 logarithm of a number.

It is equivalent to log2(x) in mathematics.

The syntax of the Math.log2() function is:

Math.log2(x)

log2(), being a static method, is called using the Math class name.


Math.log2() Parameters

The Math.log2() function takes in:

  • x - A number

Return value from Math.log2()

  • Returns the base 2 logarithm of the given number.
  • Returns NaN for negative numbers and non-numeric arguments.

Example: Using Math.log2()

// Using Math.log2()
var value = Math.log2(1);
console.log(value); // 0

var value = Math.log2(2);
console.log(value); // 1

var value = Math.log2("10");
console.log(value); // 3.321928094887362

var value = Math.log2(0);
console.log(value); // -Infinity

var value = Math.log2(-1);
console.log(value); // NaN

Output

0
1
3.321928094887362
-Infinity
NaN

Notes:

  • Use the constant Math.LOG2E for log2(e).
  • Use the functions Math.log() or Math.log10() for logarithm base e and 10.

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