System.IndexOutOfRangeException When trying populate a two-dimensional array

Question

Can any one tell me why I receive a System.IndexOutOfRangeException from this code?

char[,] matrix = new char[80, 18];
for (int i = 0; i < 80; i++)
    for (int j = 0; i < 18; j++)
        matrix[i, j] = '1';

thats what happens when you copy&paste the for loop without changing all the vars correctly. you missed the `i` in the 2nd loop. should have changed it to `j` as well — Banana, Jan 15 '15 at 15:25
Also duplicate: [What is an “index out of range” exception, and how do I fix it?](http://stackoverflow.com/questions/24812679/what-is-an-index-out-of-range-exception-and-how-do-i-fix-it) — Soner Gönül, Jan 15 '15 at 15:27

0xDEADC0DE · Answer 1 · 2015-01-15T15:25:53.150

11

You are checking if i is smaller than 18 in the second for loop

char[,] matrix = new char[80, 18];
for (int i = 0; i < 80; i++)
    for (int j = 0; i < 18; j++) //<-- Right there.
        matrix[i, j] = '1';

Change to:

char[,] matrix = new char[80, 18];
for (int i = 0; i < 80; i++)
    for (int j = 0; j < 18; j++) //<-- Right there.
        matrix[i, j] = '1';

edited Jan 15 '15 at 15:25

answered Jan 15 '15 at 15:24

0xDEADC0DE

score 4 · Answer 2 · answered Jan 15 '15 at 15:24

4

Problem : in your second for loop you are checking with variable i instead of j

for (int i = 0; i < 80; i++)
for (int j = 0; i < 18; j++)
               ^^^ should be j

Try This:

for (int i = 0; i < 80; i++)
for (int j = 0; j < 18; j++)

answered Jan 15 '15 at 15:24

score 3 · Answer 3 · answered Jan 15 '15 at 15:26

3

...because you have a typo in for (int j = 0; i < 18; j++)

answered Jan 15 '15 at 15:26

Yury Rumega

3 Answers3