What is while loop?
While loop have the following properties;
- Conditional loop structure
- Executes the statements until the given condition remains true. Stop the loop when given condition false.
When to use while loop?
- When programmer does not know in advance the total number of repetitions of loop.
What is the syntax of while loop?
| Syntax |
| While (condition) { statements; Loop increment; } |
Example:
| 1 2 3 4 5 6 7 8 9 10 11 12 13
| #include<iostream> using namespace std; int main() { int number=1; while(number<=10) { cout<<“number is “<<number<<endl; number++; } cout<<“you are outside the loop”; }
|
| Output: |
| number is 1 number is 2 number is 3 number is 4 number is 5 number is 6 number is 7 number is 8 number is 9 number is 10 you are outside the loop |
Line 5:
- Integer type loop variable “number” is declared and initialized with value 1.
Line 6:
- There is a condition that loop will execute if value of number variable is less than or equal to 10.
Line 7:
- Start of loop
Line 9:
- Value of loop variable number is incremented.
| Test Your Understandings |
| 1. If the given condition is false then no statement execute in while section? True / False |
| while(number<=10); { cout<<“number is “<<number<<endl; number++; } 2. What is the error in code above? |