setTimeout(function () { // for loop start for ( // Step 1: this is one-off: variable(s) declaration var i = 0, _ = console.log('> initialExpression'); // Step 2: this is the condition: Is `i` less than 3? i < 3 && console.log(' >> execute loopBody'), i < 3 || console.log('> loop terminates here'); // Step 3: execute only if `i` is less than 3 i++, console.log(' >> incrementExpression:', i) ) { console.log(' >>> loopBody:', i); } // for loop end }); if (typeof document !== 'undefined') { console = { log: function () { var div = document.createElement("div"), content = [].join.call(arguments, ' <b>i</b> is '); div.innerHTML = content; document.body.appendChild(div); } }; }