More "efficient" javascript - HTML Forums

Manguish · 01-07-2005, 07:23 AM

Heres a funtion i wrote for a small calculation.

It looks messy, but i was unable to get it to work doing it with brackets etc...

PHP Code:


			
function computeAnalysis( ) {

var drivespk = document.speedcalc.drive.value ;

var drivenspk = document.speedcalc.axle.value ;

var revs = document.speedcalc.rpm.value ;

var size = document.speedcalc.tiremm.value ;

var calc1 = (revs * drivespk) ;

var calc2 = (calc1 / drivenspk) ;

var calc3 = (calc2 * size) ;

var calc4 = (calc3 * 60) ;

var calc5 = (calc4 / 63360) ;



    document.speedcalc.ratio.value = (drivenspk / drivespk)

    document.speedcalc.mph.value = Math.round(calc5*10)/10

    return true

}

It's mainly the calc variables i'm looking at. Can i shorten it into a nice tidy sum?

RysChwith · 01-07-2005, 07:42 AM

PHP Code:


			
function computeAnalysis( ) { 

var drivespk = document.speedcalc.drive.value ; 

var drivenspk = document.speedcalc.axle.value ; 

var revs = document.speedcalc.rpm.value ; 

var size = document.speedcalc.tiremm.value ; 



    document.speedcalc.ratio.value = (drivenspk / drivespk) 

    document.speedcalc.mph.value = Math.round( ( ( ( ( ( revs * drivespk ) / drivenspk ) * size ) * 60 ) / 63360 * 10 ) / 10 

    return true 

}

That ought to work. Of course, given that you're using only multiplication and division, you ought to be able to remove the parentheses entirely and trust the order of operations (left to right) to handle it. I like to keep the parens in, though, just for sanity's sake.

Rys

Manguish · 01-07-2005, 07:47 AM

Cheers - i did try that but it blommin never worked

I must have missed a parentheses or something.

Cheers for confirming i'm not daft or loosing my mind though