c# - Array value seems to be different while in for loop compared to when it isn't -

i have multidimensional array values. use 2 loops loop through each item , add value them. while in array return correct value, when exits , value different. example:

• before loop: [[1,1],[2,2],[3,3]]
• during loop: [[2,2],[3,3],[4,4]]
• after loop [[50,50][65,65][90,90]]

it seems randomly change.

int[,] squareb = basesquare; int[,] squarec = basesquare; int[,] squared = basesquare; console.writeline("{0}", squareb[0, 1]); (int x = 0; x < sub; ++x) {      (int y = 0; y < sub; ++y)      {           squareb[x, y] += 9;           console.writeline("{0}", squareb[x, y]);           squarec[x, y] += 18;           squared[x, y] += 27;      } } console.writeline("{0}", squareb[0, 1]); 

you're modifying exact same array tree times @ every single loop iteration:

      squareb[x, y] += 9;       squarec[x, y] += 18;       squared[x, y] += 27; 

these change exact same value.