Function

In programming, a function is a block of code that performs a specific task and can be called (executed) multiple times. Functions allow you to group related code together and reuse it easily.

In Python, you can define a function using the def keyword, followed by the name of the function and a set of parentheses that may include parameters. The code inside the function is indented and should be written in a new block.

The syntax for defining a function in Python is as follows:

def function_name(parameters):
   # code to be executed

Here, function_name is the name of the function, and parameters are the variables that the function takes as input. The parameters are optional, so you can define a function without any parameters.

To call (execute) a function in Python, you simply need to use its name followed by a set of parentheses that may include arguments (the values to be passed to the function as input).

The syntax for calling a function in Python is as follows:

function_name(arguments)

Here, arguments are the values that are passed to the function as input. The arguments are optional, so you can call a function without any arguments.

Here is an example of how you can define and call a function in Python:

def greet(name):
   print("Hello, " + name)
greet("John")  # Output: "Hello, John"
greet("Mary")  # Output: "Hello, Mary"

In this example, the function greet() takes a single parameter name and prints a greeting message using the value of the name parameter. The function is called twice, with the arguments "John" and "Mary", and the output is "Hello, John" and "Hello, Mary" respectively.

Functions can also return a value using the return statement. The return statement specifies the value that the function should return to the caller.

Here is an example of a function that returns a value in Python:

def add(x, y):
   return x + y
result = add(3, 4)  # result will be 7
print(result)  # Output: 7

In this example, the function add() takes two parameters x and y and returns their sum. The function is called with the arguments 3 and 4, and the value 7 is assigned to the result variable. The result is then printed, and the output is “7”.