Iteration in Programming

 

📌 Iteration in Programming

Iteration refers to the process of executing a set of instructions repeatedly until a certain condition is met. It is commonly implemented using loops.

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1️⃣ Types of Iteration (Loops)

(a) Entry-Controlled Loops (Condition checked first)

🔹 For Loop → Used when the number of iterations is known.
🔹 While Loop → Used when the number of iterations is not known in advance.

(b) Exit-Controlled Loop (Condition checked after execution)

🔹 Do-While Loop → Executes at least once before checking the condition.

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2️⃣ Iteration Using Loops in C

📌 (a) For Loop (Definite Iteration)

#include <stdio.h>
int main() {
    for (int i = 1; i <= 5; i++) {
        printf("Iteration %d\n", i);
    }
    return 0;
}

🔹 Output:

nginx

Iteration 1
Iteration 2
Iteration 3
Iteration 4
Iteration 5

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📌 (b) While Loop (Indefinite Iteration)

#include <stdio.h>
int main() {
    int i = 1;
    while (i <= 5) {
        printf("Iteration %d\n", i);
        i++;
    }
    return 0;
}

🔹 Used when the number of repetitions is unknown beforehand.

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📌 (c) Do-While Loop (Execute at Least Once)

#include <stdio.h>
int main() {
    int i = 1;
    do {
        printf("Iteration %d\n", i);
        i++;
    } while (i <= 5);
    return 0;
}

🔹 Executes at least once, even if the condition is false.

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3️⃣ Iteration in Arrays (Traversing Elements)

#include <stdio.h>
int main() {
    int arr[] = {10, 20, 30, 40, 50};
    int size = sizeof(arr) / sizeof(arr[0]);

    for (int i = 0; i < size; i++) {
        printf("Element %d: %d\n", i, arr[i]);
    }
    return 0;
}

🔹 Iterates through an array using a loop.

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4️⃣ Infinite Loops (Use with Caution!)

while (1) { 
    printf("This is an infinite loop!\n"); 
}

🔹 Use break to exit an infinite loop.