PYTHON WHILE LOOP

PYTHON WHILE LOOP

The while loop can execute a block of statements repeatedly till the condition is true.

Python syntax for while loop

while condition:       Statement(s)

First the condition of while loop is checked; if it is true then the statements in the body of while loop are executed. After the execution, again the condition of while loop is checked and if it is found to be true then again the statements of while loop are executed. These statements are executed continuously till the condition is true and when the condition becomes false, the loop terminates and the control comes out of the loop.

Flow Chart of while loop

Flow Chart of while loop

Example 1: Print numbers from 1 to 10.

Coding:

#initialize num variable with 1 num=1 #check the value of num is less than equal to 10 while num<=10:     print (num) #incrementing the value of num by 1     num += 1

Output:

1 2 3 4 5 6 7 8 9 10

Example 2: Calculate the sum of numbers from 1 to 10.
Coding:

#initialize n and sum with 10 and 0 respectively num = 10 sum=0 #check the value of num is greater than equal to 0 while (num >= 0): #incrementing the value of sum by the value of num       sum = sum + num #decrement  the value of num by 1       num= num – 1 #print the value of sum variable    print ("The sum is: ", sum)

Output:

The sum is:  55

Example 3: Find the sum of digits
Coding:

#initialize sum with 0 sum=0 #store user input into num variable num=int(input("Enter the number:")) #check the value of num is greater than equal to 0 while (num >= 0):      rem = num % 10     sum = sum + rem     num = num // 10 #print the value of sum variable    print("The sum of digits:", sum)

Output:

Enter the number:444 The sum of digits: 12