Javascript Course

A while loop just looks at a short comparison and repeats until the comparison is no longer True.

The while() loop

The while() loops executes a code as long as a condition is True. If the condition starts out as false, the statements won’t execute at all.

- Syntax:
 //code to be executed
var i =0;
 document.write('<br /> i = '+i);
- First it's declared a variable 'i' with the value of 0. The 'while' statement checks the condition (here: i<5), which it's True and permits the execution of block code inside the brackets. The 'i++' increments the value of 'i' and check again the condition. The loop will stop when the 'i' reach 5.

do ... while() loops

The do...while() loop is a variant of the while() loop. First it is executed the block of code, and then it will repeat the loop as long as the specified condition is true.

do {
 //code to be executed
Here is a simple example:
var x = 8;
do {
 document.write('<br> x = '+x);
- This example display 'x = 8'.
As you can notice, although the condition is false (x<5), the code between braces is still executed once.

Daily Test with Code Example

Which HTML5 tag is indicated to be used as container for menu with navigation links in Web site?
<section> <nav> <article>
 <li><a href="" title="CSS Course">CSS Course</a></li>
 <li><a href="" title="Flash Games">Flash Games</a></li>
Which CSS property shifts an item horizontally to the left or right of where it was?
text-align clear float
.some_class {
  width: 30%;
  float: left;
Click on the Math object method which returns x, rounded downwards to the nearest integer.
Math.ceil(x) Math.abs(x) Math.floor(x)
var num = 12.34567;
num = Math.floor(num);
alert(num);       // 12
Indicate the PHP function which returns the number of characters in string.
mb_strlen() count() stristr()
$str = "string with utf-8 chars åèö";
$nrchr = mb_strlen($str);
echo $nrchr;        // 30
While loops

Last accessed pages

  1. Refresh page if window width changes from a device size to other (565)
  2. JavaScript code and PHP (34151)
  3. Wake Up! (11270)
  4. Select in MySQL, Output results in HTML Table (16001)
  5. Contact page - CoursesWeb (48293)

Popular pages this month

  1. Courses Web: PHP-MySQL JavaScript Node.js Ajax HTML CSS (520)
  2. PHP Unzipper - Extract Zip, Rar Archives (421)
  3. SHA256 Encrypt hash in JavaScript (402)
  4. Read Excel file data in PHP - PhpExcelReader (360)
  5. Create simple Website with PHP (332)