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JavaScript DOM Scripting By Example Improving the Application Code Refactor 2: Readable Branching Logic

Jonathon Irizarry
Jonathon Irizarry
9,154 Points
Posted by Jonathon Irizarry
Jonathon Irizarry
9,154 Points

Shouldn't you use function expressions?

In this video, the instructor uses function declarations inside of the 'if' blocks. Why? I thought you were supposed to use function expressions inside of the 'if' blocks in order to prevent hoisting to the top of the scope in which they appear and potential errors when declaring the function more than once. I even read from the es5 documentation this:

Several widely used implementations of ECMAScript are known to support the use of FunctionDeclaration as a Statement. However there are significant and irreconcilable variations among the implementations in the semantics applied to such FunctionDeclarations. Because of these irreconcilable difference, the use of a FunctionDeclaration as a Statement results in code that is not reliably portable among implementations. It is recommended that ECMAScript implementations either disallow this usage of FunctionDeclaration or issue a warning when such a usage is encountered. Future editions of ECMAScript may define alternative portable means for declaring functions in a Statement context.

1 Answer