Quiz: Basics | Variables | Data Types

Introduction

Quiz: Basics | Variables | Data Types checks how well you can apply Valid vs invalid identifiers and Size of int and char on your system (and related ideas) in C. Try each prompt in a scratch file before moving on.

Understanding the topic

Challenge 1 In your own words — or with a tiny program — show that you understand: Valid vs invalid identifiers.

Challenge 2 In your own words — or with a tiny program — show that you understand: Size of int and char on your system.

Challenge 3 In your own words — or with a tiny program — show that you understand: Difference between declaration and initialization.

Challenge 4 In your own words — or with a tiny program — show that you understand: Correct format specifiers for float and double.

• Challenge 1 — In your own words — or with a tiny program — show that you understand: Valid vs invalid identifiers.
• Challenge 2 — In your own words — or with a tiny program — show that you understand: Size of int and char on your system.
• Challenge 3 — In your own words — or with a tiny program — show that you understand: Difference between declaration and initialization.
• Challenge 4 — In your own words — or with a tiny program — show that you understand: Correct format specifiers for float and double.

Step-by-step explanation

1. Challenge 1 — In your own words — or with a tiny program — show that you understand: Valid vs invalid identifiers.
2. Challenge 2 — In your own words — or with a tiny program — show that you understand: Size of int and char on your system.
3. Challenge 3 — In your own words — or with a tiny program — show that you understand: Difference between declaration and initialization.
4. Challenge 4 — In your own words — or with a tiny program — show that you understand: Correct format specifiers for float and double.

Execution workflow

Best practices

• Enable warnings: gcc -Wall -Wextra -std=c11 source.c -o app
• Give every variable a defined value before it is read.
• Stay inside array bounds — C will not stop you from over-running a buffer.

Common mistakes

• Reading uninitialized storage — behavior is undefined.
• Dismissing compiler warnings instead of fixing root causes.
• Ignoring NULL returns from malloc, fopen, and similar APIs.

Hands-on exercise

Practice problems:

• Build or explain: Valid vs invalid identifiers
• Build or explain: Size of int and char on your system
• Build or explain: Difference between declaration and initialization
• Build or explain: Correct format specifiers for float and double

Summary

Quiz: Basics | Variables | Data Types in C — Self-check on declarations, types, and naming.