Module 4: Control Statements & Loops - Final Quiz MCQs

What is the output of the following C code demonstrating switch-case fallthrough?

#include <stdio.h>

int main() {
    int x = 2;
    switch (x) {
        case 1: printf("One ");
        case 2: printf("Two ");
        case 3: printf("Three ");
        default: printf("Default");
    }
    return 0;
}

What is the output of the following C code containing a trailing semicolon after if?

#include <stdio.h>

int main() {
    int a = 10;
    if (a > 20);
    {
        printf("Condition Passed ");
    }
    printf("End");
    return 0;
}

What is the output of the following do-while loop?

#include <stdio.h>

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

What is the output of the following loop utilizing the comma operator in initialization and step?

#include <stdio.h>

int main() {
    int i, j;
    for (i = 0, j = 4; i < j; i++, j--) {
        printf("%d%d ", i, j);
    }
    return 0;
}

What happens when the following code with a continue statement inside a while loop is executed?

#include <stdio.h>

int main() {
    int i = 0;
    while (i < 3) {
        if (i == 1) {
            continue;
        }
        printf("%d ", i);
        i++;
    }
    return 0;
}

What is the output of the following code illustrating the classic "Dangling Else" problem?

#include <stdio.h>

int main() {
    int x = 5, y = 10;
    if (x > 10)
        if (y > 5)
            printf("Alpha");
    else
        printf("Beta");
    return 0;
}

What is the output of this code with variable mutation across switch cases?

#include <stdio.h>

int main() {
    int a = 1;
    switch (a) {
        case 1: a += 3;
        case 2: a += 2; break;
        case 3: a += 1;
    }
    printf("%d", a);
    return 0;
}

What is the behavior of the following loop with a trailing semicolon?

#include <stdio.h>

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

Why is using a floating-point counter in the loop below considered dangerous in systems programming?

for (float f = 0.0f; f != 1.0f; f += 0.2f) {
    // ...
}