String Concatenation vs. Array.join() benchmarking for Node.js with Benchmark.js.

string_concat_join.js

var Benchmark = require('benchmark'),
  suite = Benchmark.Suite();

var COUNT = process.argv[2] - 0;
console.log(COUNT);

var data = [];
for (var i = 0; i < COUNT; i++) {
  data.push('string');
}

suite.add('Plain concatenation', function() {
  var res = '';
  for (var i = 0; i < COUNT; i++) {
    res += data[i];
  }
})
.add('String array join()', function() {
  data.join('')
})
.on('cycle', function(event) {
  console.log(String(event.target));
})
.on('complete', function() {
  console.log('Fastest is ' + this.filter('fastest').pluck('name'));
})
.run({ 'async': true });

See more details: http://www.mkaz.ru/blog/2013/01/19/plain-string-concatenation-vs-array-dot-join/

Not fair..
For real string creation, you need '1 array per 1 string'.
And you don't need to save string into array and get string from array if you use string +=

See: https://gist.github.com/ceram1/7e98b0a139185e80f22b

@mkazantsev: your link is broken