How to sum a row in a matrix

Question

Write the method:

public int sumRow(int[][] matrix, int row)

that sums row row in the 2D array called matrix.

Given:

Answer 1

there is a problem with your second for loop's condition , matrix.length is the length of first dimension , for the second dimension it looks like matrix[i].length

for(int i = 0; i < matrix.length; i++){
     for(int j = 0; j < matrix[i].length; j++){
         sum = sum + matrix[i][j];
     }   
}

i prefer to use sum+=matrix[i][j] instead of sum = sum + matrix[i][j]

calculating for one row :

for(int j = 0; j < matrix[row].length; j++){
    sum = sum + matrix[row][j];
}

just note that row's range is from 0 to matrix.length-1