Javascript optimisation

gistfile1.txt

Some quick notes from http://www.youtube.com/watch?v=UJPdhx5zTaw
Don't mix types ( be sure the array is only of one type )
Don't read out of bounds
Avoid operations with undefined values ( always initialize )
Don't add a new properties to the object during runtime
Initialize all object members in constructor functions
Always initialize object members in the same order
Use 31 bit signed numbers in critical calculations 
Don't preallocate arrays elements
Don't delete elements from arrays
Don't load from uninitialized or deleted elements.
Avoid dom operations.
Avoid types conversion.

Wrong:

var a = new Array();

a[0] = 22 //allocates
a[1] = 42
a[2] = 0.5 //allocates,converts
a[3] = true //allocates,converts

Right way:

var a = [ 22, 42, 0.5, true ];

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