Comparison of performance impact for anonymous functions with JavaScript variable versus local named functions.

Goal is to compare timing on similar set of functions(named and anonymous) for:

• Load time: JS load and compile, no execution.
  What is the impact of smaller footprint for named functions?
• Execution time of
  • Var as reference to anonymous function:
    var FunctionScr3Var27=function(){ window.RealCount=27; }
    Funtion - local named function:
    var function FunctionScr3Var27(){ window.RealCount=27; }
  • Each - full set, all functions are called
  • Half set: initialize all, but run each even function to see the promise of smaller load time for uninitialized variables.
    Set var SkipEachOdd=true; before JS include. In JS itself:
    if( !SkipEachOdd || 1 )FunctionScr3Var27();
  • Global - functions are declared in window scope.
  • Local - functions are declared in function scope:
    function GblFunctionScr3Var(){
    ...
    var FunctionScr3Var27=function(){ window.RealCount=0; } if( !SkipEachOdd || 0 )FunctionScr3Var0();
    ...
    }GblFunctionScr3Var();

Additional requirements:

• Display file size for each test
• Show backend render time
• each generated function name shall be unique to avoid hash name optimization: another test shows that overriding is faster than new declaration.
• Run test on various browsers, collect results on public blog
  http://blog.firsov.net/2010/01/js-local-functions-anonymous-vs-named.html

Sources:

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Copyright (c) 2010, Sasha Firsov, Simulation Works, LLC
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