Question

Easy question:
I’m trying to add a number to an array like this:

sorted[4][2]+=nbrMvt[i];

but it adds the two numbers as if they were strings. The output just puts the numbers one beside the other…
I have tried these methods:

sorted[4][2]+=parseInt(nbrMvt[i]);

sorted[4][2]=sorted[4][2]+nbrMvt[i];

sorted[4][2]=parseInt(sorted[4][2])+parseInt(nbrMvt[i]);

But none of them work.

[EDIT]

Ok, here is how I created my array:

var sorted = MultiDimensionalArray(13,4);

I then atribute string values to the sorted[x][0…12]
the last example gives me “NaNNaNNaNNaN”

 function MultiDimensionalArray(iRows,iCols)
  {
  var i;
  var j;
     var a = new Array(iRows);
     for (i=0; i < iRows; i++)
     {
         a[i] = new Array(iCols);
         for (j=0; j < iCols; j++)
         {
             a[i][j] = "";
         }
     }
     return(a);
  } 

(btw, what should I understand from the vote down on my question?)

Answer 1

Your MultiDimensionalArray(iRows,iCols) function is defining the array contents as strings. When you try to add a number to an element in the array like: sorted[4][2] += 2 it is just concatenating to that string.

However the following should still work, even in that instance:

sorted[4][2] = parseInt(sorted[4][2])+parseInt(nbrMvt[i]);

Unless nbrMvt[i] is in an invalid format, causing parseInt() to return NaN. Which would make the sum also NaN.

Here is jsFiddle of working code similar to yours, with a small rewrite to your MultiDimensionalArray() function.