Functions

Functions

A group of statements that perform a given task is a function. They help separate specific logic and organize the code. They can be called repeatedly to perform the same task over and over again.

Table of Contents:

• Function Definitions
• Passing values to Functions
• Scope of names
• Defining Functions
• Recursive functions

Function Definition

def func(a, b, c):
    statement_1
    statement_2
    ..
    return(v)

A function definition includes the following:

• Function Name (func)
• Arguments/Parameters (a, b,c)
• A return statement, exits the function and returns a value.
• If there is no return, function ends when last statement is reached.

Passing values to Functions

Same as defining the function, instead actual values are passed into the arguments.

def twice(n):
    return(2*n)

print(twice(12)) # 24

Scope of names

Names within the function have local scope.

Defining Functions

• A function must be defined before it is invoked.
• Interpreter reads the code from top to bottom.
• Functions are not read, but their definition is remembered.
• They're read when the function is invoked.

Recursive Functions

• A function can all itself.

def factorial(n):
    if n <= 0:
        return(1)
    else:
        val = n * factorial(n-1)
        return(val)