How to remove the last three digits from a string in php

Two removal methods: 1. Use the substr_replace() function to replace the last 3 characters of the string with the empty character "''". The syntax is "substr_replace(string,"",-3,3 )" or "substr_replace(string,"",-3)". 2. Use the substr() function to intercept all characters except the last 3 characters from the head of the string. The syntax is "substr(string,0,-3)".

The operating environment of this tutorial: windows7 system, PHP version 8.1, DELL G3 computer

In php, you can use the following two functions Remove the last three digits of the string. Remove the last three digits of the string.

• substr_replace() function

• substr() function
  

Method 1: Use the substr_replace() function to remove

The substr_replace() function can start from the specified position in the string and replace the specified Replaces a substring of length (a specified number of characters) with the specified value.

substr_replace(string,replacement,start,length)

Parameters	Description
string	Required . Specifies the string to check.
replacement	Required. Specifies the string to be inserted.
start	Required. Specifies where in the string to begin replacement. Positive number - starts at the specified position in the string Negative number - starts at the specified position from the end of the string 0 - at the first character in the string Start at
length	Optional. Specifies how many characters to replace. The default is the same as the string length. Positive number - the length of the string to be replaced Negative number - the number of characters to be replaced from the end of the string 0 - insert instead of replace

You only need to set the second parameter of the substr_replace() function to the empty string '', and set the third parameter to "-3", the fourth parameter is set to 3 or omitted to delete the last 3 digits of the string.

Example: Delete the last 3 digits of the string "hello123"

<?php
header("Content-type:text/html;charset=utf-8");
$str="hello123";
echo "原字符串：";
var_dump($str);
echo "去除字符串后三位：";
$newStr1=substr_replace($str,&#39;&#39;,-3,3);
var_dump($newStr1);
$newStr2=substr_replace($str,&#39;&#39;,-3);
var_dump($newStr2);
?>

Method 2: Use substr() Function remove

substr() function can intercept a certain length of characters from the specified position of the string and return it. This intercepted character can be called a "substring" or "subcharacter String”

substr(string,start,length)

Parameter	Description
string	Required. Specifies a part of the string to be returned.
start	Required. Specifies where in the string to begin. Positive number - starts at the specified position in the string Negative number - starts at the specified position from the end of the string 0 - at the first character in the string Start at
length	Optional. Specifies the length of the string to be returned. The default is until the end of the string. Positive number - Returns from the position of the start parameter Negative number - Returns from the end of the string

Just use the substr() function to intercept all characters except the last 3 characters from the beginning of the string:

• That is, set the second parameter of the function to 0, the third parameter is set to -3 to delete the last 3 characters.

Example: Delete the last 3 digits of the string "hello123"

<?php
header("Content-type:text/html;charset=utf-8");
$str="hello123";
echo "原字符串：";
var_dump($str);
echo "去除字符串后三位：";
$newstr=substr($str,0,-3);
var_dump($newstr);
?>

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