Add article about while loop

SamyPesse · SamyPesse · commit ac6fe15da33f · 2014-04-02T19:59:58.000-07:00
diff --git a/loops/for.md b/loops/for.md
@@ -2,7 +2,7 @@
 
 The easiest form of a loop is the for statement. This one has a syntax that is similar to an if statement, but with more options:
 
-```
+```javascript
 for(condition; end condition; change){
     // do it, do it now
 }
diff --git a/loops/while.md b/loops/while.md
@@ -0,0 +1,62 @@
+# While Loop
+
+While Loops can execute a block of code as long as a specified condition is true.
+
+```javascript
+while(condition){
+    // do it as long as condition is true
+}
+```
+
+For example, The loop in this example will continue to run as long as the variable i is less than 5:
+
+```javascript
+var i = 0, x = "";
+while (i < 5) {
+    x = x + "The number is " + i;
+    i++;
+}
+```
+
+The do/while loop is a variant of the while loop. This loop will execute the code block once, before checking if the condition is true, then it will repeat the loop as long as the condition is true:
+
+```javascript
+do {
+    // code block to be executed
+} while (condition);
+```
+
+
+**Note**: Be careful to avoid infinite looping if the condition is always true!
+
+
+---
+
+Create using a while-loop a variable named `message` which equals the concatenation of integers (1, 2, 3, ...) as long as its length (`message.length`) is inferior to 100.
+
+```js
+var message = "";
+```
+
+```js
+var message = "";
+var i = 0;
+
+while (message.length < 100) {
+    message = message + i;
+    i = i + 1;
+}
+```
+
+```js
+var message2 = "";
+var i2 = 0;
+
+while (message2.length < 100) {
+    message2 = message2 + i2;
+    i2 = i2 + 1;
+}
+assert(message == message2);
+```
+
+---

Original file line number	Diff line number	Diff line change
`@@ -2,7 +2,7 @@`
`2`	`2`
`3`	`3`	`The easiest form of a loop is the for statement. This one has a syntax that is similar to an if statement, but with more options:`
`4`	`4`
`5`		-```
	`5`	+```javascript
`6`	`6`	`for(condition; end condition; change){`
`7`	`7`	`// do it, do it now`
`8`	`8`	`}`