Posts

Showing posts from May 6, 2012

Using "use strict" in JavaScript

Image
Using Firefox, as of this writing, version 12.0. Here's a tiny part of using "use strict" syntax in JavaScript. without "use strict", var x = 17; var evalX = eval("var x = 42; x"); alert(x === 17);  // results to  false alert(x === 42);  // results to true alert(evalX === 42); // results to true with "use strict", var x = 17; var evalX = eval("'use strict'; var x = 42; x"); alert(x === 17);  // results to true alert(x === 42); // results to false alert(evalX === 42); // results to true To know more about "use strict", read more on Mozilla's page at  https://developer.mozilla.org/en/JavaScript/Strict_mode  or another interesting blog to read at  http://ejohn.org/blog/ecmascript-5-strict-mode-json-and-more/ A tabular view shows what browsers does support strict mode in JavaScript. Taken from  http://caniuse.com/#feat=use-strict , as of this writing, I got this tabular view below,