Question

1. Given the declaration

           

            char table[7][9];

           

                which of the following stores the character 'B' into the fifth row and second column of the array?

            A) table[5] = 'B';

            B)   table[2][5] = 'B';

            C)   table[5][2] = 'B';

            D) table[1][4] = 'B';

            E)   table[4][1] = 'B';

2. This program fragment is intended to zero out a two-dimensional array:

int arr[10][20];

            int i, j;

           

            for (i = 0; i < 10; i++)

                  for (j = 0; j < 20; j++)

                      // Statement is missing here

           

                What is the missing statement?

            A) arr[j+1][i+1] = 0;

            B)   arr[i-1][j-1] = 0;

            C)   arr[i+1][j+1] = 0;

            D) arr[i][j] = 0;

            E)   arr[j][i] = 0;

3. Given this nested For loops

  for (i = 0; i < M; i++)

                  for (j = 0; j < N; j++)

                      cout << arr[i][j];

           

                what is the appropriate declaration for arr?

            A) int arr[M+N];

            B)   int arr[M+1][N+1];

            C)   int arr[M][N];

            D) int arr[N][M];

            E)   int arr[N+1][M+1];

4. Given the declarations

           

            float alpha[5][50];

            float sum = 0.0;

           

                which one computes the sum of the elements in row 2 of alpha?

            A) for (i = 0; i < 50; i++)

                           sum = sum + alpha[2][i];

            B)   for (i = 0; i < 5; i++)

                           sum = sum + alpha[2][i];

            C)   for (i = 0; i < 50; i++)

                           sum = sum + alpha[i][2];

            D) for (i = 0; i < 5; i++)

                           sum = sum + alpha[i][2];

5. Look at the following array definition.

int numberArray[9][11];

Write a statement that assigns 130 to the first column of the second row of this array.

6. Write a statement which will assign 18 to the last column of the last row of this array.

Values is a two-dimensional array of floats that include 10 rows and 20 columns. Write a

code that sums all the elements in the array and stores the sum in the variable named total.

Answer 1

Ans 1: E)   table[4][1] = 'B';

The first half is used to get to the 5th row(4th index) and second part is used to get to the 2nd column(1 st index).

Ans 2: D) arr[i][j] = 0;

Since, we the row index values ranges from 0 to 9 and the column index value ranges from 0 to 19.

Ans 3: C)   int arr[M][N];

Since, we the row index values ranges from 0 to M-1 and the column index value ranges from 0 to N-1.

Ans 4: The options to this question are incorrect. Since, we need to access the second row (i.e., 1st index considering arrays are 0 index by default). The correct answer is

for (i = 0; i < 50; i++)

                           sum = sum + alpha[1][i];

Ans 5:

Write a statement that assigns 130 to the first column of the second row of this array:

=> numberArray[1][0] = 130;

Write a statement which will assign 18 to the last column of the last row of this array.

=> numberArray[8][10] = 18;

Ans 6:

float numarray[10][20];
float total = 0;
for (int i=0; i<10; i++){
    for (int j= 0; j<20; j++){
        total += numarray[i][j];
    }
}