Run results for: Map vs Reduce

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.95 Safari/537.36

Browser: Chrome 55

Operating system: Mac OS X 10.11.6

Device Platform: Other

Date tested: 7 years ago

Test name	Executions per second
Map + Array.Join	18.1 Ops/sec
Reduce + String.Concat	0.8 Ops/sec

HTML Preparation code:

<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>

Script Preparation code:

var data = [],
    numRows = 1000,
    numCols = 1000;

for (var y = 0; y < numRows; y++) {
  var lineData = [];
  for (var x = 0; x < numCols; x++) {
    lineData[x] = [131840, ' ', 1];
  }
  data[y] = lineData; 
}

Tests:

Map + Array.Join
_.map(data, function(line) { return _.map(line, function(char) { return char[1]; }).join(""); }).join("\n");
Reduce + String.Concat
_.reduce(data, function(memo, line) { return memo + _.reduce(line, function(lineMemo, char) { return lineMemo + char; }, "") + "\n" }, "");

Run results for: Map vs Reduce

Map + Array.Join

Reduce + String.Concat