How to read the last few characters of a string in php

In PHP, you can use the substr() function to read the last few characters of a string. You only need to set the second parameter of the function to a negative value and omit the third parameter; syntax "substr(string,-n)" means reading all characters from the nth character forward from the end of the string to the end of the string.

The operating environment of this tutorial: windows7 system, PHP7.1 version, DELL G3 computer

In php, you can use substr () function to read the last few characters of the string.

substr() function returns a part of a string.

You only need to omit the third parameter of the function, and set the second parameter to a negative value (-n), n specifies the last few characters you want to read

Implementation example :

<?php
header(&#39;content-type:text/html;charset=utf-8&#39;);   
$str = "abcdefg";
echo "原字符串：".$str."<br>";
echo "读取后1个字符：".substr($str,-1)."<br>";
echo "读取后2个字符：".substr($str,-2)."<br>";
echo "读取后3个字符：".substr($str,-3)."<br>";
?>

Description:

substr() function can intercept a certain length of characters from the specified position of the string. This paragraph The intercepted characters can be called "substrings" or "substrings", and their syntax format is as follows:

substr($string, $start [, $length])

Parameter description is as follows:

• $string: required The intercepted string contains at least one character;
• $start: intercepts the starting position of the string;
  • If $start is a non-negative number, then the string will be from $string Interception starts at the $start character, and $start starts counting from 0. For example, in the string "abcdef", the character at position 0 is "a", the character at position 2 is "c", etc.;
  • If $start is a negative number, the string will start from $ The end of string starts at the $start character forward, and $start starts counting from -1. For example, in the string "abcdef", the character at position -1 is "f", the character at position -3 is "d", etc.;
  • If the length of $string is less than $start, it will be returned FALSE.
• $length: Optional parameter, indicating the length of the intercepted string.
  • If $length is a positive number, then the string will be truncated up to $length characters from the $start position;
  • If $length is a negative number, then $length characters from the end of $string Characters will be omitted (if $start is a negative number, it will be counted from the end of the string);
  • If the value of $length is 0, FALSE or NULL, an empty string will be returned;
  • If $length is not provided, the returned substring will start from the $start position until the end of the string.

Recommended study: "PHP Video Tutorial"

The above is the detailed content of How to read the last few characters of a string in php. For more information, please follow other related articles on the PHP Chinese website!