While loops

do ... while() loops

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:

while(condition){
 //code to be executed
}

Example:

<script>
var i =0;
while(i<5){
 document.write('<br /> i = '+i);
 i++;
}
</script>

- 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.

Syntax:

do {
 //code to be executed
}
while(condition)

Here is a simple example:

<script>
var x = 8;
do {
 document.write('<br> x = '+x);
 x++;
}
while(x<5)
</script>

- This example display 'x = 8'.
As you can notice, although the condition is false (x<5), the code between braces is still executed once.

<<-For loops in JavaScript -- break, continue, and label->>

Daily Test with Code Example

HTML

CSS

JavaScript

PHP-MySQL

Which tag adds an image in web page?

<img src="http://coursesweb.net/imgs/webcourses.gif" width="191" height="63" alt="Courses-Web" />

Which of these CSS codes displays the text oblique?

font-style: italic; text-decoration: underline; font-weight: 500;

#id {
  font-style: italic;
}

Click on the jQuery function used to hide with animation a HTML element.

click() hide() show()

$(document).ready(function() {
  $(".a_class").click(function(){ $(this).hide("slow"); });
});

Click on the correctly defined function in PHP.

fname function() {} function fname() {} function $fname() {};

function fname($a, $b) {
  echo $a * $b;
}

Last accessed pages

Get the value of the selected /checked checkboxes in a form ^(40325)
createElement and insertBefore ⁽⁵⁹⁰²⁾
Insert, Select and Update NULL value in MySQL ^(36876)
Create simple Website with PHP ^(22297)
Get Attribute (ID, Class, Name, Title, Src) with jQuery ^(57521)

Popular pages this month

Making DIV Contents Scroll Horizontally, with multiple Div`s inside ⁽²⁴¹³⁾
Contact page - CoursesWeb ⁽²³³²⁾
Tabs effect with CSS ⁽²³²³⁾
Insert, Select and Update NULL value in MySQL ⁽¹³¹⁴⁾
PHP getElementById and getElementsByTagName ⁽⁹⁰³⁾