FivG_Pro

🔰 What Is a Function?

A function is a reusable block of code that performs a specific task.
Instead of repeating code, we can write it once and call it whenever needed.

✍️ Defining a Function

def greet():
    print("Hello, welcome to Python!")
    
greet()

✅ Output:

Hello, welcome to Python!

---

🎯 Functions with Parameters

Functions can accept parameters (inputs).

def greet(name):
    print(f"Hello, {name}!")

greet("Ali")
greet("Sara")

✅ Output:

Hello, Ali!
Hello, Sara!

---

🎯 Functions with Return Values

Functions can return data using return.

def add(a, b):
    return a + b

result = add(5, 3)
print("The sum is:", result)

✅ Output:

The sum is: 8

---

📘 Default Parameters

You can assign default values to parameters.

def greet(name="Friend"):
    print(f"Hello, {name}!")

greet()          # uses default
greet("Omar")    # overrides default

✅ Output:

Hello, Friend!
Hello, Omar!

---

🔍 Variable Scope (Local vs Global)

• Local variable: exists only inside a function.
• Global variable: exists everywhere in the program.

x = 10  # global variable

def test():
    x = 5  # local variable
    print("Inside function:", x)

test()
print("Outside function:", x)

✅ Output:

Inside function: 5
Outside function: 10

---

📦 Lambda (Anonymous Functions)

Quick one-line functions using lambda.

square = lambda x: x * x
print(square(4))

✅ Output:

16

---

🧠 Exercise 1: Calculator Functions

1. Write functions: add, subtract, multiply, divide.
2. Ask the user for two numbers.
3. Use the functions to print results.

---

🧠 Exercise 2: Scope

1. Create a global variable counter = 0.
2. Write a function that increases the counter.
3. Show the difference between modifying it locally vs globally.

---

📝 Summary

• Functions help us organize and reuse code.
• Use parameters to pass values and return to get results.
• Scope determines where variables can be accessed.
• Lambda functions are quick, single-line functions.

⬇️ Download FivG_Pro تحميل Server 1 ⬇️ Download FivG_Pro تحميل Server 2 ⬇️ Download FivG_Pro تحميل Server 3