Nested Loops

Nested Loop is located inside other loop block.

Nested for Loop

Let's have a program that prints each combination of 2 dice rolls.

# Outer loop: for i in range(1, 7): # Inner Loop: for j in range(1, 7): print(i, j)

Output:

1 1 1 2 1 3 1 4 1 5 1 6 2 1 2 2 ... 6 4 6 5 6 6

Each iteration of the outer loop executes the inner loop. Basically the outer loop repeats 6 times and the inner loop 36 (6 x 6).

Nested while Loop

Via nested loops figures like pyramids, triangles and others patterns can be printed.

Let's have a program which prints a rectangle with specific width and height

width = 5 height = 3 heightIndex = 0 while heightIndex < height: widthIndex = 0 row = "" while (widthIndex < width): row += "* " widthIndex += 1 print(row) heightIndex += 1

Output:

* * * * * * * * * * * * * * *

Any type of loop (while, for) can be nested inside other loop.