13-for Loop.md

for Loop in C Programming

Video Link: https://youtu.be/WgS_SF1VrEk Tutorial Link: https://www.programiz.com/c-programming/c-for-loop

Syntax :

for (initializationExpression; testExpression; updateExpression) {
  // code inside the for loop
}

Example 1 : print numbers from 0 to 9

#include <stdio.h>

int main() {

  for (int i = 0; i < 10; i++) {
    printf("%d ", i);
  }

  return 0;
}

Output

0 1 2 3 4 5 6 7 8 9 

Example 2 : print a message multiple times

#include <stdio.h>

int main() {

  for (int i = 0; i < 10; i++) {
    printf("Emergency condition \n");
  }

  return 0;
}

Output

Emergency condition 
Emergency condition 
Emergency condition 
Emergency condition 
Emergency condition 
Emergency condition 
Emergency condition 
Emergency condition 
Emergency condition 
Emergency condition

Sum of all the numbers from 1 to 100

#include <stdio.h>

int main() {
  
  int sum = 0;
  
  for (int i = 1; i <= 100; i++) {
    sum = sum + i;
  }

  printf("Sum: %d", sum);
  return 0;
}

Output

Sum: 5050

Sum of Even Numbers

#include <stdio.h>

int main() {
  
  int sum = 0;
  
  for (int i = 2; i <= 100; i = i + 2) {
    sum = sum + i;
  }

  printf("Sum: %d", sum);
  return 0;
}

Output

Sum: 2550

---

Programming Task

Q. Can you use the for loop to compute the sum of only odd numbers from 1 to 100. In each iteration, you need to add an odd number to the sum.

sum = sum + 1
sum = sum + 3
sum = sum + 5
....
....
sum = sum + 99

Solution :

    #include <stdio.h>

int main() {
    int sum = 0;
    for(int i = 1; i <= 100; i = i+2) {
        sum = sum + i;
    }
    printf("Sum of odd numbers from 1 to 100: %d", sum);
    
    return 0;
}

Output

Sum of odd numbers from 1 to 100: 2500

---

Programiz Quiz

Q. In the for loop below, which is the update statement?

for (int i = 1; i < 5; i++) {...}

Options:

1. int i = 1

2. i < 5

3. i++

4. for

Answer: 3