Run results for: Reduce vs map/join

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0

Browser: Firefox 63

Operating system: Windows

Device Platform: Desktop

Date tested: 5 years ago

Script Preparation code:

var strings = {};
for (var i=0; i<1000; i++) {
  strings[i] = ""+i+i;
}

Tests:

for
var result = ""; for (var i in Object.keys(strings)) { result = result+' '+i+strings[i]; }
reduce
var result = Object.keys(strings).reduce(function(string, i) { return string+' '+i+strings[i]; }, "");
map
var result = Object.keys(strings).map(function(i) { return i+' '+strings[i]; }).join(' ');