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December 2, 2016 15:47
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Functions and their scope: declarations vs. expressions
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| /* | |
| Resources: | |
| - https://javascriptweblog.wordpress.com/2010/07/06/function-declarations-vs-function-expressions/ | |
| - http://www.2ality.com/2011/04/ecmascript-5-spec-lexicalenvironment.html | |
| */ | |
| // function declarations uses the VariableEnvironment as scope | |
| function f() { | |
| return 12; | |
| } | |
| // function expressions use the LexicalEnvironment | |
| // annoymous | |
| var f = function () { | |
| return 12; | |
| }; | |
| // named | |
| var f = function foo () { | |
| return 12; | |
| }; | |
| // self invoking | |
| (function f() { | |
| return 12; | |
| })(); | |
| // Examples | |
| function foo() { | |
| var bar = function () { | |
| return 3; | |
| }; | |
| return bar(); | |
| var bar = function () { | |
| return 8; | |
| }; | |
| } | |
| console.log(foo()); // 8 | |
| function boo() { | |
| function bar() { | |
| return 3; | |
| } | |
| return bar(); | |
| function bar() { | |
| return 8; | |
| } | |
| } | |
| console.log(boo()); // 3 |
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