The while Loop, break, and continue

A while loop repeats a block of code for as long as a condition stays true. Unlike a for loop, you don't know in advance how many times it will run — it depends entirely on when the condition becomes false.

Basic while Loop

count = 0

while count < 5:
    print(count)
    count += 1
# 0 1 2 3 4

You must update the loop variable yourself inside the body. Forgetting count += 1 here would create an infinite loop, since the condition would never become false.

while True — An Intentional Infinite Loop

Sometimes you genuinely want a loop to run forever until something inside it explicitly stops it — common in menu-driven programs or servers.

while True:
    answer = input("Type 'quit' to exit: ")
    if answer == "quit":
        break
    print(f"You typed: {answer}")

The break Statement

break exits the loop immediately and completely — execution jumps straight to the first line after the loop, skipping any remaining iterations entirely.

for n in range(1, 20):
    if n == 8:
        break
    print(n)
# Prints 1 through 7, then stops the moment n equals 8

The continue Statement

continue skips only the rest of the current iteration and immediately moves to the next one — the loop itself keeps running.

for n in range(1, 10):
    if n % 2 == 0:
        continue   # skip even numbers
    print(n)
# Prints only the odd numbers: 1 3 5 7 9

break vs continue — Side by Side

break and continue Inside a while Loop

num = 0
while num < 10:
    num += 1
    if num % 2 == 0:
        continue          # skip printing even numbers
    if num == 9:
        break             # stop entirely once we reach 9
    print(num)
# Prints: 1 3 5 7

The while-else Clause

Just like for-else, a while loop's else block runs only if the loop finished normally — without being interrupted by a break.

attempts = 0
max_attempts = 3

while attempts < max_attempts:
    password = input("Enter password: ")
    if password == "secret":
        print("Access granted")
        break
    attempts += 1
else:
    print("Too many failed attempts — locked out")

Interview tip: A frequently asked trick question is "Does the else block run if the loop never executes at all (e.g. the condition is false from the very start)?" — Yes. Since no break occurred, the else block still runs even if the loop body executed zero times.