eliminate last character from string php code example

Example 1: php substr remove last 4 characters

echo substr($string, 0, -3);

Example 2: remove last character from string in php

$arrStr = 'Str1, Str2, str3, ';
echo rtrim($arrStr, ", "); //Str1, Str2, str3
echo substr_replace($arrStr, "", -2); //Str1, Str2, str3
echo substr($arrStr, 0, -2); // Str1, Str2, str3