如何删除字符串中重复的字符序列？

Question

Imagine if:

$string = "abcdabcdabcdabcdabcdabcdabcdabcd";

How do I remove the repeated sequence of characters (all characters, not just alphabets) in the string so that the new string would only have "abcd"? Perhaps running a function that returns a new string with removed repetitions.

$new_string = remove_repetitions($string);

The possible string before removing the repetition is always like above. I don’t know how else to explain since English is not my first language. Other examples are,

$string = “EqhabEqhabEqhabEqhabEqhab”;
$string = “o=98guo=98guo=98gu”;

Note that I want it to work with other sequence of characters as well. I tried using Regex but I couldn't figure out a way to accomplish it. I am still new to php and Regex.

Answer 1

For details : https://algorithms.tutorialhorizon.com/remove-duplicates-from-the-string/

In different programming have a different way to remove the same or duplicate character from a string. Example: In PHP

<?php
$str = "Hello World!";
echo count_chars($str,3);
?> 

OutPut : !HWdelor https://www.w3schools.com/php/func_string_count_chars.asp