Programming FundamentalsNot Started
Functions
Define reusable blocks of code with parameters and return values
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Explanation
A function is a reusable block of code that performs a specific task. You define it once and call it many times.
python
def greet(name):
return f"Hello, {name}!"print(greet("Alice")) # Hello, Alice! ```
Key concepts:
- def keyword starts the definition
- Parameters are inputs (name above)
- return sends a value back to the caller
- Functions with no return statement return None
- Arguments are the actual values passed when calling
Functions help you avoid repeating code (DRY — Don't Repeat Yourself).
Examples
Function with default parameter
Default parameter values make arguments optional
def power(base, exp=2):
return base ** exp
print(power(3)) # 9 (exp defaults to 2)
print(power(2, 3)) # 8Next in Programming Fundamentals
Loops