🔹 1. What is a Function?

Function ek block of code hota hai jo ek specific kaam karta hai.

Bar-bar same kaam ke liye code likhne ki jagah ek function bana lo aur usse baar-baar call karo.

📦 Think: Ek baar “dabba” bana do, fir use jitni baar chaho open karo!

🔹 2. Types of Functions

Type Example
Built-in Function sqrt(), pow(), cin, cout etc.
User-defined Function Apna banaya hua function jaise int add(int a, int b)

🔹 3. Function Syntax

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return_type function_name(parameter1, parameter2, ...) {
    // Code block
    return value;
}

🧠 Example:

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int add(int a, int b) {
    return a + b;
}

Call:

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int result = add(4, 5);

🔹 4. Function Components

Part Explanation
Return Type Kya return karega? (int, void, float)
Function Name Function ka naam
Parameters Input values (optional)
Function Body Code jo run hoga
Return Statement Kya value return karni hai

🔹 5. Function Declaration + Definition + Call

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// Declaration
int sum(int, int);

// Definition
int sum(int a, int b) {
    return a + b;
}

// Call
int ans = sum(3, 7);