What is Loop?

A loop is a control structure that allows repeated execution of a block of statements as long as a given condition remains true.

Types of Loops

• for loop – used when number of iterations is known
• while loop – used when number of iterations is unknown (entry-controlled)
• do-while loop – executes at least once (exit-controlled)

Difference Between Break and Continue Statement

Feature	break	continue
Function	Terminates the entire loop immediately	Skips the current iteration and moves to next iteration
Control	Transfers control outside the loop	Transfers control to the loop's condition check
Effect	Loop stops completely	Loop continues with next iteration
Use case	Exit loop when a condition is met	Skip specific values during iteration
Example	Breaking out when element is found	Skipping negative numbers in a sum

Example

// break example
for(int i = 1; i <= 10; i++) {
    if(i == 5)
        break;      // loop ends at i=5
    printf("%d ", i);
}
// Output: 1 2 3 4

// continue example
for(int i = 1; i <= 10; i++) {
    if(i == 5)
        continue;   // skips i=5, continues loop
    printf("%d ", i);
}
// Output: 1 2 3 4 6 7 8 9 10

Conclusion: Break exits the loop entirely, while continue only skips the current iteration and the loop keeps running.

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Program to Find Sum of First N Natural Numbers

The sum of first N natural numbers means adding all numbers from 1 to N.

#include <stdio.h>

int main() {
    int n, i, sum = 0;

    printf("Enter the value of N: ");
    scanf("%d", &n);

    for(i = 1; i <= n; i++) {
        sum = sum + i;
    }

    printf("Sum of first %d natural numbers = %d", n, sum);

    return 0;
}

Sample Output:

Enter the value of N: 5
Sum of first 5 natural numbers = 15

Explanation: The for loop runs from 1 to N, adding each value of i to the variable sum. After the loop ends, the total sum is displayed.