Which ordering of nested loops for iterating over a 2D array is more efficient [duplicate]

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The first method is slightly better, as the cells being assigned to lays next to each other.

First method:

[ ][ ][ ][ ][ ] ....
^1st assignment
   ^2nd assignment
[ ][ ][ ][ ][ ] ....
^101st assignment

Second method:

[ ][ ][ ][ ][ ] ....
^1st assignment
   ^101st assignment
[ ][ ][ ][ ][ ] ....
^2nd assignment

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