w3resource

PHP: crc32() function

Description

The crc32() function generates a 32-bit cyclic redundancy code (CRC) for a string.

The function is generally used to validate the integrity of data being transmitted.

Version:

(PHP 4 and above)

Syntax:

crc32(string_data)

Parameter:

Name Description Required /
Optional
Type
string_data The string data. Required String

Return values

The crc32 checksum of string_data.

Value Type: Integer.

Pictorial Presentation

php-string-crc32()

Example:

<?php
$crc_string = crc32('Good Morning...');
printf('%u', $crc_string);
?>

Output:

1329844137 

View the example in the browser

See also

PHP Function Reference

Previous: count_chars
Next: crypt



PHP: Tips of the Day

$_GET: An associative array of variables passed to the current script via the URL parameters

$_GET is an array that contains all the URL parameters; these are the whatever is after the ? in the URL.

Using http://www.example.com/index.php?myVar=myVal as an example. This information from this URL can be obtained by accessing in this format $_GET["myVar"] and the result of this will be myVal.

Using some code for those that don't like reading.

Example:

<?php
// URL = http://www.example.com/index.php?myVar=myVal
echo $_GET["myVar"] == "myVal" ? "true" : "false"; // returns "true"
?>

Output:

false

The above example makes use of the ternary operator.

This shows how you can access the value from the URL using the $_GET superglobal.

Now another example! gasp

// URL = http://www.example.com/index.php?myVar=myVal&myVar2=myVal2
echo $_GET["myVar"]; // returns "myVal"
echo $_GET["myVar2"]; // returns "myVal2"

Output:


It is possible to send multiple variables through the URL by separating them with an ampersand (&) character.

Security risk

It is very important not to send any sensitive information via the URL as it will stay in history of the computer and will be visible to anyone that can access that browser.