FUNCTIONS
=========
C ==> printf(), scanf(), getchar(), putchar() ==> Functional approach
PERL ==> SCRIPTING
MODULA3 ==> MODULAR APPROACH

CALCI
	ARITHMETIC
	==========
	TRIGONOMETRIC
	=============
	LOG
	====
	INTEGRATION
	===========
	DERIVATIVES
	============

CLASS

EX: 
class Hello{
	public static void main(String x[])
	{
		System.out.println("Hello World!");
	}
}

Function Vs Method:
===================
Syntax for function and method are same
function ==> can always write outside the class
method ==> can always write inside the class.

Note:
====
Java programming language has "methods"
whereas the python programming language has: both functions and methods.

What is the function?
=====================
a named block which can be use to define the specific task.
function can always be invoked/called.
function can accept a data using parameters
processing parameters
return the output.

How to define functions in Python?
==================================

keyword: def

def function-name(parameter names with comma separation):
	block of code for specific task

How to call/invoke the function?
=================================

function-name(data)

Ways to define functions
========================
==> there are 4-ways:
1) function without parameters and no return type
====================================================
Syntax:
def function-name():	# function header
	function body

# WRITING A FUNCTION WITHOUT PARAMETERS AND NO RETURN TYPE

def sumDigits():        # function header
    # function body
    number = int(input("Enter a decimal value:"))
    sum_dig = 0

    n = number

    while n != 0:
        ind_dig = n % 10
        sum_dig += ind_dig
        n //= 10

    print("The Sum of individual digits of {} is = {}".format(number,sum_dig))

sumDigits()

============================================================

2) function without parameters and return type
===============================================
Syntax:

def function-name():
	function-body
	return value

# WRITING A FUNCTION WITHOUT PARAMETERS AND RETURN TYPE

def findBig():
    a = int(input("Enter a value:"))
    b = int(input("Enter a value:"))
    c = int(input("Enter a value:"))
    d = int(input("Enter a value:"))
    e = int(input("Enter a value:"))

    if a > b and a > c and a > d and a > e:
        big = a
        return big
    elif b > c and b > d and b > e:
        big = b
        return big
    elif c > d and c > e:
        big = c
        return big
    elif d > e:
        big = d
        return big
    else:
        big = e
        return big


# bigger = findBig()
# print("The Biggest value is = ",bigger)

print("The Biggest number is = ",findBig())

======================================================
3) function with parameters and no return type
==============================================
Syntax:
	
def function-name(parameter with comma separation):
	function-body

# WRITING A FUNCTION WITH PARAMETERS AND NO RETURN TYPE

def typeTriangle(s1,s2,s3):
    if s1 == s2 == s3:
        print("It is an Equilateral Triangle.")

    elif s1 == s2 or s1 == s3 or s3 == s2:
        print("It is an Isosceles Triangle.")

    elif (s1 ** 2 + s2 ** 2) == s3 ** 2 or (s1 ** 2 + s3 ** 2) == s2 ** 2 or (s2 ** 2 + s3 ** 2) == s1 ** 2:
        print("It is a Right Angled Triangle.")

    else:
        print("It is a Scalene Triangle.")

# typeTriangle(11,11,11)

# s1 = 10
# s2 = 11
# s3 = 10
# typeTriangle(s1,s2,s3)

# a = 3
# b = 4
# c = 5
# typeTriangle(c,a,b)

p = 9
q = 10
r = 11
typeTriangle(s1 = r,s2 = p, s3 = q)

4) function with parameters and return type
===========================================
Syntax:

def function-name(parameters):
	function-body
	return statement

# WRITING A PYTHON FUNCTION WHICH CAN ACCEPT PARAMETERS AND RETURNING A VALUE.

def findAreaOfTriangle(a,b,c):
    s = (a + b + c)/2

    area = (s * (s-a) * (s-b) * (s-c))**0.5

    return area

print("The Area of the Triangle is = ",findAreaOfTriangle(7,9,8))

===================================================

Types of Parameters:
====================
Parameters ==> Arguments
two types of parameters:
	1) Actual Arguments
	2) Formal Arguments

the arguments which we can define in function header ==> formal arguments
the arguments which we can define in function call ==> actual arguments