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

PHP: How to write to the console in PHP?

Firefox

On Firefox you can use an extension called FirePHP which enables the logging and dumping of information from your PHP applications to the console. This is an addon to the awesome web development extension Firebug.

  • http://www.studytrails.com/blog/using-firephp-in-firefox-to-debug-php/

Chrome

However if you are using Chrome there is a PHP debugging tool called Chrome Logger or webug (webug has problems with the order of logs).

More recently Clockwork is in active development which extends the Developer Tools by adding a new panel to provide useful debugging and profiling information. It provides out of the box support for Laravel 4 and Slim 2 and support can be added via its extensible API.

Using Xdebug

A better way to debug your PHP would be via Xdebug. Most browsers provide helper extensions to help you pass the required cookie/query string to initialize the debugging process.

  • Chrome - Xdebug Helper
  • Firefox - The easiest Xdebug
  • Opera - Xdebug
  • Safari - Xdebug Toggler

Ref : https://bit.ly/3ck9rFg