Using substr() with negative length

 
<?
print substr('This is a test. This is another test.',15,-2);
print substr('This is a test. This is another test.',-4,-1);
?>

1.	A negative substr() length parameter
2.	A positive substr() length parameter
3.	Accessing Substrings: string substr ( string string, int start [, int length] )
4.	Extracting Part of a String with substr()
5.	Extracting a substring with substr()
6.	Extracting the end of a string with substr()
7.	If you pass substr() a negative number, it counts from the end of the string.
8.	Setting up and working with both strings and substrings
9.	Single-character substitutions
10.	Truncating a string with substr()
11.	Using substr() with length past the end of the string
12.	Using substr() with negative start
13.	Using substr() with positive $start and $length
14.	Using substr() with positive start and no length
15.	string substr ( string str, int start_pos [, int length] ) reads part of a string and takes a minimum of two parameters
16.	substr() function returns the part of the string between the start and start+length parameters.
17.	substr-2.php
18.	substr-3.php
19.	substr.php
20.	Specify a negative number as parameter three for the length
21.	Using negative lengths allows you to say "copy everything but the last three characters,"
22.	Reading Fixed-Width Delimited Data

Using substr() with negative length : substr « String « PHP