C Variables
What is Variables?
A variable in C is like a container used to store data during program execution. It holds a value that can change while the program runs.
Imagine you want to remember a number—like a score or age. You give that number a name like score or age, and your computer remembers it using that name. That's a variable.
Types of Variables in C
Each variable needs a type, which tells the computer what kind of information it holds:
| Type | Description | Example |
|---|---|---|
| int | Whole numbers | int marks = 90; |
| float | Decimal numbers | float price = 99.5; |
| char | Single letters | char grade = 'A'; |
| double | Large decimal numbers | double pi = 3.14159; |
| bool | True/false values (with stdbool.h) | bool isReady = true; |
How to Declare a Variable
int age; float weight; Char initial;
This means you're telling C: "I will use a number (age), a decimal (weight), and a character (initial)."
How to Assign Values
age = 25; weight = 65.5; Initial = 'S';
You can also do both steps in one line:
int age = 25;
Strict Notes – Must Remember
- Declaration before usage is compulsory.
- Names must begin with a letter or underscore (_).
- No spaces or special characters (except _) in identifiers.
- C is case-sensitive – Age and age are different.
- Cannot use reserved words like int, while, return as variable names.
- Use semicolon (;) at the end of every statement.
- Type mismatch (e.g., assigning float to int) may cause incorrect results.
- Variable names should be meaningful to improve code readability.
- Re-declaration in the same block is an error.
- Uninitialized variables may contain garbage values.
Unique Vocabulary
- Identifier
- Reserved
- Literal
- Scope
- Memory
- Instruction
- Precision
- Dataflow
- Constant
- Symbol
Final Thoughts
C provides a versatile set of types: from raw numbers to flexible memory-sharing structures. Understanding how each works allows you to optimize space, enhance readability, and increase code efficiency
Prefer Learning by Watching?
Watch these YouTube tutorials to understand C Tutorial visually:
What You'll Learn:
- 📌 #2: C Variables and Print Output | [2025] C Programming for Beginners
- 📌 Introduction to Variables