Benchmark str concatenation

bench.js

var Benchmark = require('benchmark');

var suite = new Benchmark.Suite,
    a, b;

global.str = 'TextTextTextTextTextTextTextTextTextTextTextTextTextTextText\n';
global.str2 = 'TextTextTextTextTextTextTextTextTextTextTextTextTextTextText\\n';

var statement = 'var str = global.str;\nvar s=';
for (i=0; i<100; i++)
  if (i!=99)
    statement += 'str+';
  else
    statement += 'str;';
var fn = new Function('', statement);


var statement2 = 'var s=';
for (i=0; i<100; i++)
  if (i!=99)
    statement2 += '"'+global.str2+'"+';
  else
    statement2 += '"'+global.str2+'";';
var fn2 = new Function('', statement2);

var statement3 = 'var str = global.str;\nvar s=';
for (i=0; i<100; i++)
  if (i!=99 && i%2)
    statement3 += '"'+global.str2+'"+';
  else if (i%2==0)
    statement3 += 'str+';
  else
    statement3 += '"'+global.str2+'";';
var fn3 = new Function('', statement3);

suite
.add('push', function () {
  a = [];
  var str = global.str;
  for (var i = 0; i < 100; i++)
    a.push(str);
  b = a.join();
})
.add('add', function () {
  b = '';
  var str = global.str;
  for (var i = 0; i < 100; i++)
    b += str;
})
.add('concat', fn)
.add('litconcat', fn2)
.add('mixedconcat', fn3)
.on('cycle', function (event, bench) {
  console.log(bench.toString());
})
.on('complete', function () {
  console.log('Fastest is ' + this.filter('fastest').pluck('name'));
})
.run();

push x 293,764 ops/sec ±0.80% (54 runs sampled)
add x 644,289 ops/sec ±4.85% (44 runs sampled)
concat x 878,138 ops/sec ±3.62% (47 runs sampled)
litconcat x 7,195,488 ops/sec ±254.21% (6 runs sampled)
mixedconcat x 880,040 ops/sec ±3.48% (48 runs sampled)
Fastest is litconcat