Loop unlooping in Javascript
Few days ago I’ve read a book ‘Even Faster Web Sites‘ about websites optimisation and I found one thing usefuluseful, not only on websites. There was a small tip about looploop unlooping. I want to quote them for later use. First - with switch statement var iterations = Math.ceil(values.length / 8); var startAt = values.length % 8; var i = 0; do { switch(startAt) { case 0: process(values[i++]); case 7: process(values[i++]); case 6: process(values[i++]); case 5: process(values[i++]); case 4: process(values[i++]); case 3: process(values[i++]); case 2: process(values[i++]); case 1: process(values[i++]); } startAt = 0; } while(--iterations > 0); Second - without switch var iterations = Math.floor(values.length / 8); var leftover = values.length % 8; var i = 0; if(leftover > 0) { do { process(values[i++]); } while(--leftover > 0); } do { process(values[i++]); process(values[i++]); process(values[i++]); process(values[i++]); process(values[i++]); process(values[i++]); process(values[i++]); process(values[i++]); } while (--iterations > 0); I found second example more readable and I prefer it. These examples after translation could be easily used in other scripting languages. ...