Question

Here is a simple code :

var a:Array = new Array( ins0, ins1, ins2, ins3,...., ins10000) ;
findIns( ins1500) ;

function findIns( ins:SomeInstance ) {  
    for ( var i = 0 ; i< a.length ; i++)  {
        if ( a[i] == ins ) {
            trace ( "FOUND IT");
            break; 
        }
    }
}

In the above code there is NO “int” or “string”. They are instances of some complex class. So is it sensible to use Vectors in place of arrays in this case.

In my opinion it should be sensible, because instances are “numerical-memory-locations” afterall ?

Answer 1

If the content of the array are all instances of the same class, then yes Vector will definitely performs better than Array.

See the documentation for more information:

• Performance: array element access and iteration are much faster when using a Vector instance than they are when using an Array.

• Type safety: in strict mode the compiler can identify data type errors. Examples of data type errors include assigning a value of the incorrect data type to a Vector or expecting the wrong data type when reading a value from a Vector. Note, however, that when using the push() method or unshift() method to add values to a Vector, the arguments’ data types are not checked at compile time. Instead, they are checked at run time.

• Reliability: runtime range checking (or fixed-length checking) increases reliability significantly over Arrays.

http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/Vector.html