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PHP: substr_compare() function

Description

The substr_compare() function is used to compare two strings from a given starting position in the main string.

Version:

(PHP 5)

Syntax:

substr_compare(main_string, compare_string, star_pos, length, case_insensitivity)

Parameters:

Name Description Required /
Optional
Type
main_string The main string. Required String
compare_string The string to be compared. Required String
star_pos The starting position in the main string. Required Integer
length A positive number : Start at the specified position in the string.
A negative number : Start at a specified position from the end of the string.
Optional Integer
case_insensitivity If set TRUE comparison is case insensitive. Optional Boolean

Return value:

0 : If two main_string=compare_string
<0 : if the length of the main_string from the starting position is less than the compare_string
>0 : if the length of the main_string from the starting position is greater than the compare_string.

Value Type: Integer.

Pictorial Presentation

string_substr_compare

Example:

<?php
echo substr_compare('uvwxyz', 'uv', 1, 2).'<br>';
echo substr_compare('uvwxyz', 'uvw', 1, 2).'<br>';
echo substr_compare('uvwxyz', 'uv', -2, 2).'<br>';
echo substr_compare('uvwxyz', 'xy', 1, 2).'<br>';
echo substr_compare('uvwxyz', 'xyz', -3, 3).'<br>';
?>

Output:

1
1
4
-2
0 

View the example in the browser

See also

PHP Function Reference

Previous: strtr
Next: substr_count



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.