#!/usr/bin/env python
# coding: utf-8

# # 1. Simple function

# In[2]:


def foo():
    print("This is foo")

foo()


# # 2. Function with parameters

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def bar(x, y):
    print("Sum is ", x + y)
    
bar(3, 5)


# # 3. Default parameter value

# In[5]:


def drawLine(length = 10):
    str = ""
    for i in range(0, length):
        str += "_"
    print(str)

drawLine()

drawLine(40)

drawLine(length=20)


# # 4. Lambda expressions

# In[6]:


def greeter(val):
  return lambda x: val + x

greet = greeter("Hello ")

print(greet("Alice!"))
print(greet("Bob!"))


# # 5. Recursive functions

# In[1]:


def factorial(x):
    if x == 1:
        return 1
    else:
        return (x * factorial(x-1))

x = 4
print("The factorial of", x, "is", factorial(x))