回答編集履歴
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比較まとめ
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### 比較まとめ
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コードの最適化を進めた上で比較してみました。
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```JavaScript
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var bench = new Array(10000000);
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var sTime, fTime;
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/**
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* _.each
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*/
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sTime = new Date();
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var sqrt = Math.sqrt,
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pow = Math.pow;
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_.each(bench, function (value, index) {
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bench[index] = sqrt(pow(12345) + pow(53142));
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});
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fTime = new Date();
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console.log('_.each', fTime - sTime);
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/**
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* Array.prototype.forEach
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*/
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sTime = new Date();
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var sqrt = Math.sqrt,
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pow = Math.pow;
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bench.forEach(function (value, index, array) {
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array[index] = sqrt(pow(12345) + pow(53142));
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});
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fTime = new Date();
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console.log('Array.prototype.forEach', fTime - sTime);
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/**
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* for
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*/
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sTime = new Date();
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for (var i = 0, len = bench.length, sqrt = Math.sqrt, pow = Math.pow; i < len; i++) {
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bench[i] = sqrt(pow(12345) + pow(53142));
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}
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fTime = new Date();
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console.log('for', fTime - sTime);
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/**
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* while
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*/
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sTime = new Date();
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var i = bench.length,
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sqrt = Math.sqrt,
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pow = Math.pow;
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while (i--) {
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bench[i] = sqrt(pow(12345) + pow(53142));
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}
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fTime = new Date();
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console.log('while', fTime - sTime);
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```
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私の環境では、次の結果となりました。
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```JavaScript
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"_.each 899"
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"Array.prototype.forEach 658"
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"for 574"
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"while 570"
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```
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- ライブラリはネイティブ機能に勝てません。
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- 繰り返し処理において、関数呼び出しは制御構文(while, for 等)よりも遅いです。
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### 更新履歴
|
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300
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+
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301
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303
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- 2017/08/22 23:40 「比較まとめ」の節を追記
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159
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Re: airulove さん
|