Caches array length in flattenStyles methods for loop

ManasJayanth · Facebook Github Bot 9 · commit 21c433d99855 · 2016-03-26T06:54:18.000-07:00
Summary:Gains minor perf improvement in the for loop by caching the array length Closes #6671 Differential Revision: D3102064 fb-gh-sync-id: 2303d83f3672a2768c60d0e5dae999b1dda0d6bd fbshipit-source-id: 2303d83f3672a2768c60d0e5dae999b1dda0d6bd
diff --git a/Libraries/StyleSheet/flattenStyle.js b/Libraries/StyleSheet/flattenStyle.js
@@ -34,7 +34,7 @@ function flattenStyle(style: ?StyleObj): ?Object {
   }
 
   var result = {};
-  for (var i = 0; i < style.length; ++i) {
+  for (var i = 0, styleLength = style.length; i < styleLength; ++i) {
     var computedStyle = flattenStyle(style[i]);
     if (computedStyle) {
       for (var key in computedStyle) {

Original file line number	Diff line number	Diff line change
`@@ -34,7 +34,7 @@ function flattenStyle(style: ?StyleObj): ?Object {`
`34`	`34`	`}`
`35`	`35`
`36`	`36`	`var result = {};`
`37`		`- for (var i = 0; i < style.length; ++i) {`
	`37`	`+ for (var i = 0, styleLength = style.length; i < styleLength; ++i) {`
`38`	`38`	`var computedStyle = flattenStyle(style[i]);`
`39`	`39`	`if (computedStyle) {`
`40`	`40`	`for (var key in computedStyle) {`