loop.md

Loop

1. While Loop

• Syntax:

  while condition:
      code

• Example: Print numbers from 1 to 10.

  i = 1
  while i <= 10:
      print(i)
      i += 1

2. While Loop - Reverse Counting

• Example: Print numbers from 5 to 1.

  i = 5
  while i >= 1:
      print(i)
      i -= 1

3. Print Numbers from 1 to 100

• Example:

  i = 1
  while i <= 100:
      print(i)
      i += 1

4. Print Numbers from 100 to 1

• Example:

  i = 100
  while i >= 1:
      print(i)
      i -= 1

5. Multiplication Table of a Given Number

• Example:

  n = int(input("Enter a number:"))
  i = 1
  while i <= 10:
      print(n * i)
      i += 1

6. Loop Through List

• Example:

  num = [1, 4, 9, 16, 25, 36, 49, 64, 81, 100]
  idx = 0
  while idx < len(num):
      print(num[idx])
      idx += 1

7. Search a Number in a Tuple

• Example:

  x = 9
  num = (1, 4, 9, 16, 25, 36, 49, 64, 81, 100)
  i = 0
  while i < len(num):
      if num[i] == x:
          print("Found")
      i += 1

8. Break and Continue

• Break: Stops the loop.

  i = 1
  while i <= 5:
      print(i)
      if i == 3:
          break
      i += 1

• Continue: Skips the current iteration and continues to the next one.

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

9. For Loop - Sequential Traversal

• Example with a list:

  num = [1, 4, 9, 16, 25, 36, 49, 64, 81, 100]
  for val in num:
      print(val)

• Example with a tuple:

  tup = (1, 4, 9, 16, 25, 36, 49, 64, 81, 100)
  for num in tup:
      print(num)

• Example with a string:

  str = "noushad"
  for char in str:
      print(char)

10. Using Range Function

• Generate a sequence of numbers:

  seq = range(10)  # range(stop)
  for i in seq:
      print(i)

• Example with start and stop:

  for i in range(2, 10):  # range(start, stop)
      print(i)

• Example with step:

  for i in range(2, 10, 2):  # range(start, stop, step)
      print(i)

11. Print Even Numbers

• Example:

  for i in range(2, 101, 2):
      print(i)

12. Print Numbers 1 to 100

• Example:

  for i in range(1, 101):
      print(i)

13. Print Numbers 100 to 1

• Example:

  for i in range(100, 0, -1):
      print(i)

14. Multiplication Table of a Number

• Example:

  n = int(input("Enter a number:"))
  for i in range(1, 11):
      print(n * i)

15. Pass Statement

• Used when you need to write a block of code but don't want to execute it yet.

  for i in range(10):
      pass
  print("Some useful work")

16. Sum of First n Numbers

• Example:

  n = 5
  sum = 0
  for i in range(1, n + 1):
      sum += i
  print("Total sum is", sum)

17. Factorial of a Number Using For Loop

• Example:

  n = 5
  fact = 1
  for i in range(1, n + 1):
      fact *= i
  print("Factorial of", n, "is", fact)