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Function

A function is a type of subprogram that carries out a task and returns a value.
You can use the result of a function elsewhere in your program, such as storing it in a variable or using it in a decision.

def add_nums():
    num1 = int(input("Enter first number"))
    num2 = int(input("Enter second number"))
    total = num1 + num2
    return total

#Main
total = add_nums()
print("The total is", total)


	
def add_nums(num1, num2):
    total = num1 + num2
    return total

#Main
total = add_nums(6,4)
print("The total is", total)

Key features of functions

  • Has a name so it can be called when needed

  • Can take inputs (called parameters)

  • Returns a value to the main program

  • Used when you need a result from a task

Why use functions?

  • Organises your code into smaller, easy-to-understand sections

  • Returns data to use elsewhere

  • Avoids repetition – write once, use many times

  • Makes your code easier to test and fix

  • Helps with teamwork, as different people can work on different procedures concurrently