10.10. Common Mistakes¶

forgetting to create the array - only declaring it (int[][] nums;).

using 1 as the first index not 0 for rows and/or columns.

using array.length as the last valid row index, not array.length - 1.

using array[0].length as the last valid column index, not array[0].length - 1.

using array.length() instead of array.length (not penalized on the free response)

going out of bounds when looping through an array (using index <= array.length). You will get an ArrayIndexOutOfBoundsException.

jumping out an loop by using one or more return statements before every value has been processed.

using the wrong starting and ending indices on loops.

using array.length for both the number of rows and columns. Use array[0].length for the number of columns.