Merge pull request GitbookIO#76 from sumn2u/master

an example to show do while loop

en/SUMMARY.md

@@ -24,6 +24,7 @@
 * [Loops](loops/README.md)
     * [For](loops/for.md)
     * [While](loops/while.md)
+    * [Do...While](loops/dowhile.md)
 * [Functions](functions/README.md)
     * [Declare](functions/declare.md)
     * [Higher order](functions/higher_order.md)

en/loops/dowhile.md

@@ -0,0 +1,35 @@
+# Do...While Loop
+
+The do...while statement creates a loop that executes a specified statement until the test condition evaluates to be false. The condition is evaluated after executing the statement. 
+Syntax for do... while is 
+
+```javascript
+do{
+    // statement
+}
+while(expression) ; 
+```
+
+Lets for example see how to print numbers less than 10 using `do...while` loop:
+
+```
+var i = 0;
+do {
+    document.write(i + " ");
+    i++; // incrementing i by 1  
+} while (i < 10);
+```
+
+>***Note***: `i = i + 1` can be written `i++`.
+
+
+{% exercise %}
+Using a do...while-loop, print numbers between less than 5.
+{% initial %}
+var i = 0;
+{% solution %}
+var i = 0;
+do {
+    i++; // incrementing i by 1 
+} while (i < 5);
+{% endexercise %}