AS3 Tutorial: for each in resolution Efficiency

New for each... Besides traversing XML, in can also be used to traverse arrays and objects. Create "millions of troops ":

VaR testarr: array = new array ();

For (var I: Number = 0; I <1000000; I ++)

{

Testarr. Push (I );

}

Previous for and... In and the new for each... In loop:

// For 260 milliseconds

VaR Len: Number = testarr. length;

For (var j: Number = 0; j <Len; j ++)

{

Testarr [J] ++;

}

//... In 8000 milliseconds

For (var k: String in testarr)

{

Testarr [k] ++;

}

// For each... In 58 Ms

For each (var m: Number in testarr)

{

M ++;

}

How efficient is it? After multiple tests, the average length of the For Loop is 260 milliseconds (the average length of the non-Pre-stored array is 400 milliseconds),... The average in cycle is 8000 milliseconds, for each... In loop 58 Ms !! So try to avoid... In, for each... In, if you use a for loop, it is best to prestore the array length (VAR Len: Number = testarr. length ;).

Object,... Average in 560 ms, for each... The average in time is 8 ms.

VaR testobj: Object = new object ();

For (var I: Number = 0; I <100000; I ++)

{

Testobj [I] = I + 1;

}

//... In reads tags in 560 milliseconds

For (var j: String in testobj)

{

Testobj [J] ++;

}

// For each... In direct read value: 8 ms

For each (var k: Number in testobj)

{

K ++;

} From http://www.jinflex.com/index.php/archives/91