Improving code readability - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of nested if-else with clear indentation

What is the output of this C code snippet?

C

#include <stdio.h>

int main() {
    int x = 5;
    if (x > 3) {
        if (x < 10) {
            printf("Inside range\n");
        } else {
            printf("Too large\n");
        }
    } else {
        printf("Too small\n");
    }
    return 0;
}

A Inside range

B Too large

C Too small

D No output

💡 Hint

Check the conditions carefully and follow the indentation to see which block runs.

The variable x is 5, which is greater than 3 and less than 10, so the first inner if condition is true. The program prints "Inside range".

🧠 Conceptual

intermediate

Best practice for variable naming

Which variable name is the most readable and follows good naming conventions in C?

A int numberOfStudents;

B int x;

C int n;

D int a1;

💡 Hint

Think about names that clearly describe what the variable holds.

Variable names should be descriptive and meaningful. 'numberOfStudents' clearly tells what the variable represents, improving code readability.

🔧 Debug

advanced

Identify the readability issue in this code

What is the main readability problem in this C code snippet?

C

int main(){int a=10;int b=20;if(a>b){printf("A is bigger\n");}else{printf("B is bigger\n");}return 0;}

A Missing semicolons

B Incorrect use of printf

C Lack of spaces and indentation makes it hard to read

D Variables are not declared

💡 Hint

Look at how the code is spaced and arranged.

The code lacks proper spacing and indentation, making it difficult to follow. Adding spaces and new lines improves readability.

📝 Syntax

advanced

Which option causes a syntax error?

Which of the following C code snippets will cause a syntax error?

A if (x > 0) printf("Positive\n");

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

C

if (x > 0)
    printf("Positive\n");

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

💡 Hint

Remember the syntax rules for if statements in C.

Option B is missing parentheses around the condition and uses braces incorrectly, causing a syntax error.

🚀 Application

expert

How many items are printed by this loop?

Consider this C code. How many lines will it print?

C

#include <stdio.h>

int main() {
    for (int i = 0; i < 10; i++) {
        if (i % 2 == 0) {
            printf("%d\n", i);
        }
    }
    return 0;
}

A 0

B 10

C 9

D 5

💡 Hint

Count how many numbers from 0 to 9 are even.

The loop prints numbers from 0 to 9 that are even. These are 0, 2, 4, 6, 8 — a total of 5 lines.