Convert string array to array of numbers

Hello all,

I need to help with converting string array "15,0,25,40" loaded from txt file to array of numbers so I can use it e.g. with geometricBounds like this:

tx1.geometricBounds = [15,0,25,40];

I have tryed to search the internet but none of sample codes worked

Thanks very much in advance to everyone willing to help...