C Language Test 3

    Question 1: Floating-Point Data Type

    How do you declare a variable named pi to store the value 3.14159 with high precision?

    Question 2: Pre-increment Operator

    What is the value of y after the following C code executes?

    #include <stdio.h>

int main() {
    int x = 5;
    int y = ++x;
    return 0;
}

    Question 3: The default case

    The default case in a switch statement serves what purpose?

    Question 4: Continue Statement

    What does the continue statement do inside a loop?

    Question 5: Function with Parameters

    What will be the output?

    #include <stdio.h>

int add(int a, int b) {
    return a + b;
}

int main() {
    printf("%d", add(3, 4));
    return 0;
}

    Question 6: Array and Loop

    What will be printed?

    #include <stdio.h>

int main() {
    int arr[4] = {2, 4, 6, 8};
    for (int i = 0; i < 4; i++) {
        printf("%d ", arr[i]);
    }
    return 0;
}

    Question 7: NULL Pointer

    What does a NULL pointer represent in C?

    Question 8: Difference between Structure and Union

    What is the key difference between structure and union in C?

    Question 9: File Modes

    What does mode "a" do in fopen()?

    Question 10: strcat() Function

    What will be printed?

    #include <stdio.h>
#include <string.h>

int main() {
    char str1[20] = "Hi ";
    char str2[] = "C";
    strcat(str1, str2);
    printf("%s", str1);
    return 0;
}

    Question 11: Guess the Output - Type Promotion

    What is the output of the following code?

    #include <stdio.h>

int main() {
    int a = 10;
    float b = 3.0;
    printf("%.2f", a / b);
    return 0;
}

    Question 12: Post-decrement Operator

    What will be the final value of x after the following C code executes?

    #include <stdio.h>

int main() {
    int x = 8;
    int y = x--;
    return 0;
}

    Question 13: Simple If Statement

    What is the output of the following C code?

    #include 

int main() {
    int x = 10;
    if (x == 10) {
        printf("True");
    } else {
        printf("False");
    }
    return 0;
}

    Question 14: For Loop Output

    What will be printed?

    #include <stdio.h>

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

    Question 15: Function Call by Value

    What will be printed?

    #include <stdio.h>

void change(int x) {
    x = 100;
}

int main() {
    int a = 5;
    change(a);
    printf("%d", a);
    return 0;
}

    Question 16: Array Out of Bounds

    What happens if we try to access arr[10] when arr has size 5?

    Question 17: Pointer and Array

    What will be the output?

    #include <stdio.h>

int main() {
    int arr[] = {10, 20, 30};
    int *p = arr;
    printf("%d", *(p+1));
    return 0;
}

    Question 18: Size of Structure

    What will sizeof return?

    #include <stdio.h>

struct Test {
    int a;
    char b;
};

int main() {
    printf("%zu", sizeof(struct Test));
    return 0;
}

    Question 19: fgetc() Function

    What will be the output if input.txt contains AB?

    #include <stdio.h>

int main() {
    FILE *fp = fopen("input.txt", "r");
    char ch = fgetc(fp);
    printf("%c", ch);
    fclose(fp);
    return 0;
}

    Question 20: strcmp() Function

    What will strcmp("apple", "apple") return?