log < Math < JavaScript

The Math log() static method returns the natural logarithm (base e) of a number.

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

    // 2 x 2 x 2 = 8
    console.log(getBaseLog(2, 8));
    // 3

    // 5 x 5 x 5 x 5 = 625
    console.log(getBaseLog(5, 625));
    // 4