Python While Loop - Fullstackadda

while loop in Python works in just the same way as a while loop in any other programming language. Python While Loop

The while loop which is basically a set of statements in the body of the loop which execute as many times as necessary whilst the loop’s condition is true. Eventually, the statements in the loop will cause the condition to become false, causing the loop to terminate.

while expression:
    body of while

Example:

n = 1
while n < 5:  # Declare loop with condition
   print(n) 
   n = n+1

While loop with else Statement:

else part is executed after the condition in the while loop is executed.

n = 1
while n < 4:
  print(n)
  n += 1
else:
  print("Loop ended")

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Loop ended

While loop with break Statement:

break statement provides you the opportunity to exit out of a loop when an external condition is triggered. You’ll put the break statement within the block of code under your loop statement.

n = 1
while n < 10:
  print(n)
  if n == 5:
    break
  n += 1

BREAK statement applied as long as the condition is true
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5

While loop with continue Statement:

continue statement is opposite to that of break statement, instead of terminating the loop, it forces to execute the next iteration of the loop.

As the name suggests the continue statement forces the loop to continue or execute the next iteration. When the continue statement is executed in the loop, the code inside the loop following the continue statement will be skipped and the next iteration of the loop will begin.

n = 0
while n < 5:
  n += 1
  if n == 3:
    continue
  print(n)

for loop vs while loop

Here is a table that compares the for loop and the while loop in Python:

`for` loop	`while` loop
The `for` loop is used to iterate over a sequence (such as a list, tuple, or string) or other iterable object.	The `while` loop is used to repeatedly execute a block of code as long as a certain condition is true.
The `for` loop has a definite iteration, that is, the loop variable takes on all the values in the sequence.	The `while` loop has an indefinite iteration, that is, the loop variable takes on values until the condition is no longer true.
The `for` loop is best used when you know the number of iterations in advance.	The `while` loop is best used when you don’t know the number of iterations in advance.
The `for` loop is less prone to errors since it is definite iteration.	The `while` loop is more prone to errors since it is indefinite iteration and if the condition is never met then the loop will run indefinitely.

Here is an example of a for loop:

fruits = ['apple', 'banana', 'cherry']
for x in fruits:
    print(x)

apple
banana
cherry

Here is an example of a while loop:

i = 1
while i < 6:
  print(i)
  i += 1

It’s important to note that while loop can be used to achieve the same functionality as a for loop but with a different approach and sometimes for loop can’t be used in certain situations where while loop can be used.

while loop in Python works in just the same way as a while loop in any other programming language.
The while loop which is basically a set of statements in the body of the loop which execute as many times as necessary whilst the loop’s condition is true.
break statement provides you the opportunity to exit out of a loop.
continue statement is opposite to that of break statement, instead of terminating the loop, it forces to execute the next iteration of the loop.