Python · control flow

Break & Continue

Leave a loop early with break, or skip the rest of one pass with continue.

Reading the loop panels

The items

Each loop panel shows the values the loop walks over; the highlighted cell is the current one.

What happened

0printed2skipped by continue5break6never reached

The break statement


          # break exits the loop
          for i in range(10):
              if i == 5:
                  break
              print(i)
          # ans: 0, 1, 2, 3, 4

The continue statement


          # continue skips current iteration
          for i in range(5):
              if i == 2:
                  continue
              print(i)
          # ans: 0, 1, 3, 4

Break in while


          # break in while loop
          count = 0
          while True:
              count += 1
              if count == 3:
                  break
          # ans: count is 3

while True never ends on its own: break is the only way out.

Continue in while


          # continue in while
          x = 0
          while x < 5:
              x += 1
              if x == 3:
                  continue
              print(x)
          # ans: 1, 2, 4, 5 (skips 3)

The x += 1 comes before the continue; put it after and the loop would never end.

Break in a nested loop


          # break only exits inner loop
          for i in range(3):
              for j in range(3):
                  if j == 1:
                      break
                  print(f"i={i}, j={j}")
          # ans: i=0,j=0 then i=1,j=0 then i=2,j=0

Exercises

Write down the output, then press → to run the loop.

Exercise 1


          # what prints?
          for i in range(5):
              if i == 3:
                  break
              print(i)
          # ans: 0, 1, 2

Exercise 2


          # continue effect?
          for i in range(5):
              if i % 2 == 0:
                  continue
              print(i)
          # ans: 1, 3 (skips even numbers)

Exercise 3


          # multiple breaks?
          for i in range(10):
              if i == 3:
                  break
              if i == 5:
                  break
              print(i)
          # ans: 0, 1, 2 (first break stops it)

Exercise 4


          # what is i?
          for i in range(10):
              if i == 5:
                  break
          # ans: i is 5

Exercise 5


          # nested break?
          for i in range(3):
              for j in range(3):
                  if i == j == 1:
                      break
                  print(i, j)
          # ans: (0,0) (0,1) (0,2) (1,0) (2,0) (2,1) (2,2)

Exercise 6


          # what happens?
          for i in range(5):
              continue
              print(i)
          # ans: nothing (continue skips print)

Exercise 7


          # tricky continue?
          for i in range(3):
              if i == 1:
                  i = 10
                  continue
              print(i)
          # ans: 0, 2 (i=10 doesn't affect next iteration)

Exercise 8


          # what prints?
          for i in range(5):
              if i < 2:
                  continue
              if i > 3:
                  break
              print(i)
          # ans: 2, 3

Exercise 9


          # break immediately?
          for i in range(5):
              break
              print(i)
          # ans: nothing (breaks before print)

Exercise 10


          # continue then break?
          for i in range(10):
              if i % 2 == 0:
                  continue
              if i == 5:
                  break
              print(i)
          # ans: 1, 3

Remember

break

Leaves the loop at once; the remaining items are never reached.

continue

Skips the rest of this pass and goes straight to the next item.

Innermost only

In nested loops, both affect only the loop they are directly inside.

The loop variable

After a break, it keeps the value it had; changing it inside a for does not change the next item.