PHP Different characters in the given string

Different characters in a given string refer to the unique, non-repeating characters that appear within the string. Identifying these characters involves recognizing each distinct character while excluding any duplicates. This concept is useful in various programming and data analysis tasks where understanding the diversity of characters is important.

Examples:

Input : $str = "GeeksforGeeks"
Output : Gefkors
Explanation, the unique characters in the given
string $str in ascending order are G, e, f, k, 
o, r and s

Input : $str = "Computer Science Portal"
Output : CPSaceilmnoprtu
Explanation, the unique characters in the given 
string $str are C, P, S, a, c, ei, l, m, n, o, 
p, r, t and u

Using count_chars()

The count_chars() function in PHP can be used to collect all unique characters from a string. When used with return mode 3, it returns a string with all different characters used in the given string in ascending order.

Example : The uniqueCharacters function in PHP returns a string containing unique characters from the input string. It uses count_chars($str, 3).

<?php
function uniqueCharacters($str) {
    return count_chars($str, 3);
}

// Example 1
$str1 = "GeeksforGeeks";
echo uniqueCharacters($str1); // Output: Gefkors
echo "\n";

// Example 2
$str2 = "Computer Science Portal";
echo uniqueCharacters($str2); // Output: CPSaceilmnoprtu
?>

Gefkors
 CPSaceilmnoprtu

Using array_unique and sort

Use array_unique and sort in PHP to find unique characters from a string and sort them in ascending order. Convert the string to an array, remove duplicates, sort the array, and join it back into a string.

Example: The uniqueCharacters function in PHP returns a string of unique, sorted characters from the input string. It splits the string, removes duplicates, sorts the characters, and joins them back

<?php
function uniqueCharacters($str) {
    $chars = str_split($str);
    $uniqueChars = array_unique($chars);
    sort($uniqueChars);
    return implode('', $uniqueChars);
}


echo uniqueCharacters("GeeksforGeeks");
echo "\n";
echo uniqueCharacters("Computer Science Portal"); 
?>

Gefkors
 CPSaceilmnoprtu