Javascript array won't change inside of for loop

Question

I am trying to rotate a 2dimensional array in javascript

the code outside the forloop to switch the values works but when i try to do that inside the for loop the variables are not changing

i think it is some sort of reference problem and i searched for that but i can't find a solution to this problem

temp = tempboard[0][1];
    console.log("unchanged:"+tempboard[0][1]+""+tempboard[6][1]);
    tempboard[0][1] = tempboard[6][1];
    tempboard[6][1] = temp;
    console.log("changed:"+tempboard[0][1]+""+tempboard[6][1]);
    
    for(i = 0; i < board.length; i++){
        for(j = 0; j < board[0].length; j++){
            /*a = tempboard[i][j];
            b = tempboard[j][i];
            temp = a;
            a = b;
            b = temp;
            console.log(a+" "+b);*/
            temp = tempboard[i][j];
            console.log("unchanged:"+tempboard[i][j]+""+tempboard[j][i]);
            tempboard[i][j] = tempboard[j][i];
            tempboard[j][i] = temp;
            console.log("changed:"+tempboard[j][i]+""+tempboard[i][j]);
        }
    }

Answer 1

Try adding "let" keyword to your for loop, it could be an hoisting issue;

for(let i = 0; i < board.length; i++){
        for(let j = 0; j < board[0].length; j++){
            /*a = tempboard[i][j];
            b = tempboard[j][i];
            temp = a;
            a = b;
            b = temp;
            console.log(a+" "+b);*/
            temp = tempboard[i][j];
            console.log("unchanged:"+tempboard[i][j]+""+tempboard[j][i]);
            tempboard[i][j] = tempboard[j][i];
            tempboard[j][i] = temp;
            console.log("changed:"+tempboard[j][i]+""+tempboard[i][j]);
        }
    }