How to Use While Loops in Python with Examples

📚 Quick Study Guide

• 🔄 A `while` loop executes a block of code as long as a condition is true.
• 🔑 The condition is checked at the beginning of each iteration. If the condition is false initially, the loop never executes.
• ⚠️ Be careful to avoid infinite loops! Ensure the condition eventually becomes false within the loop.
• 🔢 You can use `break` to exit a `while` loop prematurely and `continue` to skip to the next iteration.
• ✏️ Syntax: `while condition: # code to execute`

🧪 Practice Quiz

1. Which statement best describes a `while` loop in Python?
   1. A) It executes a block of code once.
   2. B) It executes a block of code as long as a condition is true.
   3. C) It executes a block of code a fixed number of times.
   4. D) It is not used for looping.
2. What happens if the condition in a `while` loop is always true?
   1. A) The loop executes once and terminates.
   2. B) The loop does not execute.
   3. C) The loop becomes an infinite loop.
   4. D) The program crashes.
3. Which keyword is used to exit a `while` loop prematurely?
   1. A) `exit`
   2. B) `stop`
   3. C) `break`
   4. D) `return`
4. What is the output of the following code? python i = 1 while i < 5: print(i) i += 1
   1. A) 1 2 3 4 5
   2. B) 1 2 3 4
   3. C) 2 3 4 5
   4. D) 0 1 2 3 4
5. Which keyword is used to skip the current iteration and move to the next in a `while` loop?
   1. A) `skip`
   2. B) `next`
   3. C) `continue`
   4. D) `pass`
6. What is the value of `x` after the following code is executed? python x = 0 while x < 3: x += 1 else: x += 2
   1. A) 3
   2. B) 5
   3. C) 4
   4. D) 6
7. Which of the following is the correct syntax for a `while` loop?
   1. A) `while condition { #code }`
   2. B) `while (condition) : #code`
   3. C) `while condition: #code`
   4. D) `while: condition #code`