w3resource

PHP: substr() function

Description

The substr() function used to cut a part of a string from a string, starting at a specified position.

Version:

(PHP 4 and above)

Syntax:

substr(string_name, start_pos, length_to_cut)

Parameters:

Name Description Required /
Optional		 Type
string_name The input string. Required String
start_pos Refers to the position of the string to start cutting.
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.		 Required Integer
length_to_cut Length of the string to cut from the main string.
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

Return value:

Returns the extracted part of string and false when failure.

Value Type: String.

Pictorial Presentation

string_substr

Example - 1: 

<?php
$string1="Welcome to w3resource.com";
echo $string1;
echo '<br>';
echo substr($string1,1);
echo '<br>';
echo substr($string1,1,5);
echo '<br>';
echo substr($string1,0,10);
echo '<br>';
echo substr($string1,-1,1);
echo '<br>';
?>

Output: 

Welcome to w3resource.com
elcome to w3resource.com
elcom
Welcome   to
m

View the example in the browser

Example - 2 : 

<?php
$string1="Welcome to w3resource.com";
echo $string1;
echo '<br>';
echo substr($string1,0,-1);
echo '<br>';
echo substr($string1,3,-3);
echo '<br>';
echo substr($string1,4,-4);
echo '<br>';
echo substr($string1,-3,-2);
echo '<br>';
?>

Output :

Welcome to w3resource.com
Welcome to w3resource.co
come to   w3resource.
ome to w3resource
c

View the example in the browser

Example - 3 :

<?php
$string1="Welcome to w3resource.com";
echo $string1;
echo '<br>';
echo substr($string1,-1);
echo '<br>';
echo substr($string1,-4);
echo '<br>';
echo substr($string1,-5,1);
?>

Output :

Welcome to w3resource.com
m
.com
e

View the example in the browser

See also

PHP Function Reference

Previous: substr_replace
Next: trim



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.