gistfile1.js

function time(){
    var time = process.hrtime();
    return (time[0] * 1000) + (time[1] / 1000000);
}

var start = time();
var tmp = [];
for (var i = 0; i < 10000; i++){
    tmp.push("test");
}
tmp.join("");
console.log("Join took", time() - start + "ms");

start = time();
tmp = "";
for (var i = 0; i < 10000; i++){
    tmp += "test";
}
console.log("Concat took", time() - start + "ms");