Using return codes - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this C program using return codes?

Consider the following C program. What will it print when run?

C

#include <stdio.h>

int check(int x) {
    if (x > 0) return 1;
    else if (x == 0) return 0;
    else return -1;
}

int main() {
    int result = check(-5);
    if (result == 1) printf("Positive\n");
    else if (result == 0) printf("Zero\n");
    else printf("Negative\n");
    return 0;
}

A Negative

B Zero

C Positive

D Compilation error

💡 Hint

Look at the return values of the check function and what main does with them.

The function check returns -1 when the input is less than 0. Since -5 is less than 0, result is -1, so the program prints "Negative".

❓ Predict Output

intermediate

What is the return value of this function?

What value does the function process return when called with process(10)?

C

int process(int n) {
    if (n % 2 == 0) return 0;
    else return 1;
}

A 0

B 1

C 10

D -1

💡 Hint

Check if 10 is even or odd.

Since 10 is even, n % 2 == 0 is true, so the function returns 0.

🔧 Debug

advanced

What error does this code produce?

What error will this C code produce when compiled?

C

int check(int x) {
    if (x > 0) return 1;
    else if (x == 0) return 0;
    // Missing return for negative x
}

int main() {
    int r = check(-1);
    return 0;
}

A Segmentation fault at runtime

B Warning: control reaches end of non-void function

C Syntax error: missing semicolon

D No error, runs fine

💡 Hint

Think about what happens if x is negative.

The function check does not return a value if x < 0. This causes a compiler warning that control reaches the end of a non-void function without returning a value.

🚀 Application

advanced

How many different return codes does this function produce?

How many distinct return codes can the function status produce?

C

int status(int code) {
    switch(code) {
        case 0: return 100;
        case 1: return 200;
        case 2: return 300;
        default: return 400;
    }
}

A 3

B 2

C 5

D 4

💡 Hint

Count all unique return values possible from the switch cases including default.

The function returns 100, 200, 300, or 400 depending on the input. That is 4 distinct return codes.

🧠 Conceptual

expert

What is the best way to use return codes for error handling in C?

Which option correctly describes the best practice for using return codes in C functions to indicate success or failure?

A Return positive numbers for success and negative for failure

B Always return -1 for any error and 1 for success

C Return 0 for success and non-zero for different error types

D Use return codes only for success, errors should be printed inside the function

💡 Hint

Think about common C conventions for return codes.

In C, the common convention is to return 0 to indicate success and non-zero values to indicate different error types. This allows easy checking of success or failure.