Benchmarking RegExp and String procedure in JavaScript https://github.com/bestiejs/benchmark.js

match-pattern-benchmark.js

// $ npm i --save benchmark microtime
const Benchmark = require('benchmark')

const suite = new Benchmark.Suite
const str = 'E0123'
const compiledRegex = new RegExp(/E\d{4}/)

suite
  .add('RegExp#match', function() {
    const matched = str.match(/E\d+/)
    return matched[0] && matched[0].length === 4
  })
  .add('RegExp#match(4-lengthed)', function() {
    const matched = str.match(/E\d{4}/)
    return Boolean(matched[0])
  })
  .add('Compiled RegExp#match(4-lengthed)', function() {
    const matched = str.match(compiledRegex)
    return Boolean(matched[0])
  })
  .add('String procedure', function() {
    if(!str.startsWith('E')) {
        return false
    }
    const sub = str.substring(1, 5)
    if(sub.length != 4) {
        return false
    }
    const parsed = parseInt(sub, 10);
    if (isNaN(parsed)) { return false; }
    return true
  })
  .on('cycle', function(event) {
    console.log(String(event.target))
  })
  .on('complete', function() {
    console.log('Fastest is ' + this.filter('fastest').map('name'))
  })
  .run({ 'async': true });

stdout

RegExp#match x 14,625,424 ops/sec ±5.23% (76 runs sampled)
RegExp#match(4-lengthed) x 16,273,825 ops/sec ±1.97% (90 runs sampled)
Compiled RegExp#match(4-lengthed) x 17,805,892 ops/sec ±4.04% (88 runs sampled)
String procedure x 13,121,956 ops/sec ±1.17% (87 runs sampled)
Fastest is Compiled RegExp#match(4-lengthed)