Python Nested loops

Nested Loops:

• Defining a loop inside another loop.
• Inner loop condition evaluates only when outer condition is valid.
• Execution terminate only when outer condition fails.

Nested while loop codes:

• The following code snippets are used to analyze and understand the flow of nested loop.
• If outer loop is true, then only control checks inner loop condition.
• Inner loop executes as long as condition is valid before the second iteration of outer loop.

Snippet-1: Outer loop execute once and inner loop infinite times as condition always true.

while True:
    print("Hi")
    while True:
        print("Hello")

Snippet-2: Loop executes many times where as block executes only once. Inner block executes once every time control enters into loop with outer condition.

while True:
    print("Hi")
    if True:
        print("Hello")

Check the Output and analyze the code:

i=1
while i<=5:
    print("Outer i :",i)
    i=i+1

    j=1
    while j<=3:
        print("Inner j :",j)
        j=j+1