Node.js test

decimalCount.js

function countRegex(value) {
  var match = ('' + value).match(/(?:\.(\d+))?(?:[eE]([+-]?\d+))?$/);
  if (!match) {
    return 0;
  }
  return Math.max(0, (match[1] ? match[1].length : 0) - (match[2] ? +match[2] : 0));
}

function countParse(value) {
  var data = parseFloat(value).toString().split('.');
  if (data[1]) {
    return data[1].length;
  }
  return 0;
}

function countNumber(value) {
  var data = Number(value).toString().split('.');
  if (data[1]) {
    return data[1].length;
  }
  return 0;
}

const numbers = new Array(100000000).map(() => Math.random() * 1000);

[countRegex, countParse, countNumber].forEach((fn) => {
  const start = process.hrtime();
  const unusedTmp = numbers.map(fn); /* jshint ignore:line */
  const stop = process.hrtime(start);
  console.log(`${fn.name}	${stop[0]}s ${stop[1]}ns`);
});