Summary - Loops

Combine for, while and nested loops to write a multiplication table.

Summary - Loops

In this section you learned for, while, do-while, break, continue and nested loops. Now we'll combine them in a multiplication table app.

The multiplication table is the classic example of nested loops: the outer loop produces rows, the inner produces columns. Then we'll add a while menu loop.

Exercise 3x3 multiplication table

Write a C program. Write an outer for (int i = 1; i <= 3; i++) and inner for (int j = 1; j <= 3; j++) loop. In the inner loop print printf("%d ", i * j);. At the end of the outer print printf("\n");. Put #include <stdio.h> at the top.

Show example solution

#include <stdio.h>

int main(void) {
    for (int i = 1; i <= 3; i++) {
        for (int j = 1; j <= 3; j++) {
            printf("%d ", i * j);
        }
        printf("\n");
    }
    return 0;
}

Exercise 1 to 5 with while

Write a C program. Declare int i = 1;. Use a while (i <= 5) loop to print printf("%d\n", i); and increment with i++;. Put #include <stdio.h> at the top.

Show example solution

#include <stdio.h>

int main(void) {
    int i = 1;
    while (i <= 5) {
        printf("%d\n", i);
        i++;
    }
    return 0;
}

Test yourself

Which loop builds a multiplication table?
```
for (i=1; i<=n; i++)
  for (j=1; j<=n; j++)
    printf("%d ", i*j);
```
- Single while
- Switch
- Single do-while
- Nested for
Show answer

Nested for — The multiplication table uses nested for loops.

End the do-while

do {
    scanf("%d", &choice);
} ____ (choice == 1);

Show answer

do {
    scanf("%d", &choice);
} while (choice == 1);

Match loop and control

for

Counted
while

Conditional
do-while

At least once
break

Exit

Next lesson: Cart design

We Are Enhancing Your Experience

Cookie Preferences

Strictly Necessary Cookies

Analytical Cookies