What is a function and how to define a function
Creating Your Own Functions
function provides us a way to group statement. After we create a function we can call the function by using the function name.
To create a function we use def keyword.
def hello(name):
return 'Hello, ' + name + '!'
print hello('world')
The code above generates the following result.
A function that returns a list of the numbers of the Fibonacci series
def fib2(n): # return Fibonacci series up to n
"""Return a list containing the Fibonacci series up to n."""
result = []# w w w . j a v a 2s . co m
a, b = 0, 1
while b < n:
result.append(b) # see below
a, b = b, a+b
return result
f100 = fib2(100) # call it
print f100 # write the result
The code above generates the following result.
Forward References
The following code shows that we can forward reference a function.
# from w ww . jav a 2 s .c o m
def bar():
print 'in bar()'
def foo():
print 'in foo()'
bar()
foo()
The code above generates the following result.
In fact, we can even declare foo() before bar():
def foo():# w w w . j a v a2s. c om
print 'in foo()'
bar()
def bar():
print 'in bar()'
foo()
The code above generates the following result.
An inner function
def foo():# from ww w . j a v a 2 s.c o m
def bar():
print 'bar() called'
print 'foo() called'
bar()
foo()
The code above generates the following result.
