1. C Programming
Language
By:
Yogendra Pal
yogendra@learnbywatch.com
Dedicated to My mother and Father

2. Keep your notebook with you.
Write important point and questions that comes in your mind
Solve Mind band exercise.
Rewind when not clear
Ask Questions by call or SMS or by mail
Keep Watching Keep Learning
THIS IS STORAGE CLASS

3. Introduction
• Variables have data types and storage classes.
• Value in a computer can be stored in
– Memory or
– CPU registers
• A storage class determines where to store the
value of a variable.

4. Storage class
• Storage class determines • 4 storage classes
– Where to store – Automatic
– Default initial value – Register
– Scope – Static
– Life – External

5. Automatic
• Keyword: auto
• Default storage class.
– Where : Memory
– Initial value : Garbage
– Scope : Local to the block
– Life : Till control remain within the block.

6. Register
• Keyword: register
• Faster access then automatic.
– Where : CPU registers
– Initial value : Garbage
– Scope : Local to the block
– Life : Till control remain within the block.
• Registers are limited.
• If no register is free compiler treat it as auto.

7. Static
• Keyword: static
– Where : Memory
– Initial value : Zero
– Scope : Local to the block
– Life : Persists between function calls.
• Use when really required.

8. External
• Keyword: extern
• Define outside of each function.
– Where : Memory
– Initial value : Zero
– Scope : Global
– Life : Till program terminates
• Use when really required.

9. To get complete benefit of this tutorial solve all the quiz on
www.learnbywatch.com
For any problem in this tutorial mail me at
yogendra@learnbywatch.com
with the subject “C”
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