The Trivial Things You Can Learn When Stress Testing an AJAX Application

Friday, January 18, 2008

Internet Explorer has no problem creating an array of 65,536 elements.

var array = [];

for(var i = 0; i < 65535; i++)

{

    array.push(i);

}    

array.push(i);

alert(array.length); // says 65536

However, IE does have a problem eval-ing an array of 65,536 elements.

var buffer = '[0';

for(var i = 0; i < 65535 / 15; i++)

{

    buffer += ',0,0,0,0,0,0,0,0,0,0,0,0,0,0,0';

}

buffer += ']';

var array = eval(buffer);    

alert(array.length); // would be 65536, 

                     // if it got this far..

The code produces an out of memory error on the eval statement. The limit for eval appears to be 65,535 – a number that harkens back to the dark, dismal days of programming in a segmented memory architecture.

Of course, if you came here looking for the upper limits of eval – you might be doing something wrong!

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