JAVASCRIPT WHILE LOOP
while loops are the loop that executes the loop body until condition is true. In the while loop, condition is evaluated before entering the loop body.
If condition evaluated to true
then while loop executes the body, if condition is
false
then loop breaks out.
while loop is also known as pretest
loop because it executes
statement before execution of body.
This is the syntax of while
loop:
while(condition){ //loop body }
Here flow diagram of while
loop.
Let's see an example of while loop.
Code Explanation: In the above script
- First, outside the
while loop
a variable count is set to 0 - Second, before entering loop condition is checked, if count is smaller than 10
- Third, inside body in each iteration count is increased by 1, in 10 iteration count becomes 10 and condition get false and loop terminates
Using Variable in while loop
The count variable in the above example can be used in the loop body to get desired output like executing mathematical operations using variables, using variables to loop through arrays, etc.
Lets see an example and understand.