[HTML 5 Performance] Benchmark functions runtime in chrome console

Sometimes you'd like to measure how two implementations compare in regards to run time. In this lesson you will learn how to quickly do this using Console.time and constole.timeEnd.

    function runFaster() { 
      for (let i = 0; i < ROWS; i++) {
        for (let j = 0; j < COLS; j++) {
          arr[i * ROWS + j] = 0;
        }
      }
    }

    function runSlower() {
      for (let i = 0; i < COLS; i++) {
        for (let j = 0; j < ROWS; j++) {
          arr[j * ROWS + i] = 0;
        }
      }
    }

    const ROWS = 1000;
    const COLS = 1000;

    const arr = new Array(ROWS * COLS).fill(0);

    function testFunctionRuntime(repeats, functionToTest, logText = 'Benchmarking') {
        console.time(logText);
        for (let i = 0; i < repeats; i++) {
            functionToTest();
        }
        console.timeEnd(logText);
    }