C For Loop

C for Loop (Complete Tutorial: Beginner → Advanced)

The for loop in C language is used when you know in advance how many times a block of code should execute.
It is one of the most commonly used loops in C, especially in DSA, arrays, and interviews.

 What is a for Loop?

A for loop repeatedly executes a block of code until a given condition becomes false.

Syntax of for Loop

Execution Order

1. Initialization (once)

2. Condition check

3. Loop body

4. Increment / Decrement

5. Repeat from step 2

 Simple for Loop Example

 Output:

for Loop with Decrement

Output:

 Infinite for Loop

•  Runs forever
• Must use break to stop

for Loop with Multiple Variables

•  Useful in advanced logic

for Loop with Arrays

• Very common in DSA

Nested for Loop (Pattern Programs)

Output:

break and continue in for Loop

break – Exit Loop

 Output: 1 2

continue – Skip Iteration

Output: 1 2 4 5

for Loop Without Body

•  Semicolon makes loop body empty
   Output: 5

for Loop vs while Loop

Common Mistakes

•  Using = instead of == in condition
•  Infinite loop due to wrong condition
•  Forgetting increment/decrement
• Extra semicolon after for

 Interview Questions (Must Prepare)

1. Difference between for and while

2. Can for loop run without initialization?

3. What is for(;;)?

4. Can we use multiple variables in for loop?

5. Difference between break and continue

Real-Life Use Cases

• Array traversal

• Pattern printing

• Searching & sorting

• Embedded loops

• Competitive programming

Summary

• for loop is ideal for known iterations
• Supports initialization, condition & update
•  Can be nested and infinite
•  Essential for DSA & interviews