Control Structure

🧭 Control Structures in C

Control structures determine the flow of execution in a program. They help in decision making, looping, and jumping to specific parts of the program.

1. if Statement: Executes a block if a condition is true.

if (x > 0) {
    printf("Positive");
}

2. if-else Statement: Executes one block if true, another if false.

if (x % 2 == 0) {
    printf("Even");
} else {
    printf("Odd");
}

3. Nested if-else: if or if-else inside another if or else block.

if (x > 0) {
    if (x < 100) {
        printf("Positive and less than 100");
    }
}

4. switch Statement: Used when multiple cases depend on a single variable.

switch (choice) {
    case 1: printf("One"); break;
    case 2: printf("Two"); break;
    default: printf("Invalid");
}

1. while Loop: Checks condition first, then executes block repeatedly.

int i = 0;
while (i < 5) {
    printf("%d", i);
    i++;
}

2. do-while Loop: Executes block once before checking condition.

int i = 0;
do {
    printf("%d", i);
    i++;
} while (i < 5);

3. for Loop: Best for known number of iterations.

for (int i = 1; i <= 5; i++) {
    printf("%d ", i);
}

4. Nested for Loop: One for loop inside another.

for (int i = 1; i <= 3; i++) {
    for (int j = 1; j <= 2; j++) {
        printf("%d %d\n", i, j);
    }
}

1. break: Exits a loop or switch immediately.

for (int i = 0; i < 5; i++) {
    if (i == 3) break;
    printf("%d", i);
}

2. continue: Skips the rest of loop body for current iteration.

for (int i = 0; i < 5; i++) {
    if (i == 2) continue;
    printf("%d", i);
}

3. goto: Jumps to a labeled part of the program (use with caution).

goto label;
printf("This won't print");
label:
printf("Jumped here");

4. exit(): Terminates the program immediately.

if (error) {
    printf("Exiting...");
    exit(0);
}