Is their a way to find the closest number to 0 in an Array ?

[Stephdidou]

I've got an array like that

var tideArray = new Array(); 
tideArray.push({tide:"pmm", difference: -2}); 
tideArray.push({tide:"pms", difference: 5}); 
tideArray.push({tide:"bmm", difference: -7}); 
tideArray.push({tide:"bms", difference: 8});  

tideArray.sortOn("difference", Array.NUMERIC); 
trace(tideArray[0].tide);

For now, it's choosing the minimum number (-7) but I'd like to choose the closest number to 0.

Is there a way to do that ?

[dmennenoh · Accepted solution]

I don't think sort or sortOn will do what you want. Here's a little method that will return the index of the array element closes tto zero:

var tideArray = new Array(); 
tideArray.push({tide:"pmm", difference: -2}); 
tideArray.push({tide:"pms", difference: 5}); 
tideArray.push({tide:"bmm", difference: -7}); 
tideArray.push({tide:"bms", difference: 8}); 
trace(closestToZero(tideArray));
function closestToZero(a:Array):int
{
var curDelta:int = Math.abs(0 - a[0].difference);
var curIndex:int = 0;
for(var i:int = 1; i < a.length; i++){
var thisDelta:int = Math.abs(0 - a.difference);
if(thisDelta < curDelta){
curIndex = i;
}
}
return curIndex;
}

[Stephdidou]

Hmm not sure that is working...

I've tested and it returns "1"

If I change  the values, for example to :

tideArray.push({tide:"pmm", difference: 3});
tideArray.push({tide:"pms", difference: -4});
tideArray.push({tide:"bmm", difference: 10});
tideArray.push({tide:"bms", difference: 8});
trace(closestToZero(tideArray)); //// output 0 (it should output 3)

Also, is it possible to output the name of the array ? (in this example, I'd like to output "pmm" because it's the closest to 0)

[dmennenoh]

The output is correct - it's the array index not the value...

If you want the value:

var i:int = closestToZero(tideArray);

trace(tideArray.difference);

And if you want name too:

trace(tideArray.name, tideArray.difference);

[Stephdidou]

Oh sorry , my bad. I read to quickly ! Thanks !!!

[Stephdidou]

Hmm, in fact, I don't know why but sometimes the results are wrong.

I've tried this  :

var tideArray = new Array();
tideArray.push({tide:"haute", difference: "-14"});
tideArray.push({tide:"haute", difference: "-3"});
tideArray.push({tide:"basse", difference: "-9"});
tideArray.push({tide:"basse", difference: "4"});

trace(closestToZero(tideArray));
function closestToZero(a:Array):int  {  
var curDelta:int = Math.abs(0 - a[0].difference);  
var curIndex:int = 0;  

for(var i:int = 1; i < a.length; i++){  
var thisDelta:int = Math.abs(0 - a.difference);  
if(thisDelta < curDelta){  
curIndex = i;  
}  
}  

return curIndex;  
} 

The output is 3 (so the 4th array that is equal to 4). But, the closest to 0 is not the fourth one, but the second one (-3)..

Do you know why the code make this mistake ?

[dmennenoh]

Yes... not sure how but this line is missing:

curDelta = thisDelta;

that goes inside the if statement where curIndex is set to i - so:

1. if(thisDelta < curDelta){   
2. curIndex = i;   
3. curDelta = thisDelta;
4. }