Added warning for infinite while statements (#22805)

This commit is contained in:
JMVL64
2018-11-27 10:25:55 +01:00
committed by Kristofer Koishigawa
parent ed5e131f2f
commit 71177b5465

View File

@ -1,42 +1,61 @@
---
title: While Loop
---
The while loop starts by evaluating the condition. If the condition is true, the statement(s) is/are executed. If the condition is false, the statement(s) is/are not executed. After that, while loop ends.
The `while` loop starts by evaluating the condition. If the condition is true, the statement(s) is/are executed. If the condition is false, the statement(s) is/are not executed and the `while` loop ends. `while` loops deserve some attention, since you will create an infinite loop if the false condition is never met. An infinite loop can crash your application or browser, so make sure all the `while` loops in your code are finite.
Here is the **syntax** for while loop:
Here is the **syntax** for the `while` loop:
## Syntax:
while (condition)
{
statement(s);
}
```javascript
while (condition) {
statement(s);
}
```
_statement(s):_ A statement that is executed as long as the condition evaluates to true.
_condition:_ Here, condition is a Boolean expression which is evaluated before each pass through the loop. If this condition evaluates to true, statement(s) is/are executed. When condition evaluates to false, execution continues with the statement after the while loop.
## Example:
```javascript
let i = 1;
while (i < 10) {
console.log(i);
i++; // same as i = i + 1
}
var i = 1;
while (i < 10)
{
console.log(i);
i++; // i=i+1 same thing
}
Output:
1
2
3
4
5
6
7
8
9
```
Output:
1
2
3
4
5
6
7
8
9
## Example of an infite loop:
```javascript
let x = 0;
while (x < 10) {
console.log(x);
x--; // same as i = i - 1
}
*Source: [While Loop - MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/while)*
Output:
0
-1
-2
-3
-4
-5
-6
-7
-8
-9
...etc.
```
### Other Resources
* [MDN - while](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/while)