Question

How to remove even frequency characters from a string in PHP

Answer 1

function remove_even_frequency_characters(string $s) { 
    $char_frequency = array();
    
    for ($i = 0; $i < strlen($s); $i++) { 
        if (!isset($char_frequency[$s[$i]])) {
            $char_frequency[$s[$i]] = 0;
        } 
        $char_frequency[$s[$i]]++; 
    } 
    $new_s = "";
    for ($i = 0; $i < strlen($s); $i++) { 
        if ($char_frequency[$s[$i]] % 2 == 0) {
            continue; 
        }
        $new_s .= $s[$i]; 
    } 
    return $new_s;
} 


$s = "php programming version 7.3";

$s = remove_even_frequency_characters($s); 

echo $s;


 
/*
run:
 
php prra vers 7.3 
    
*/

 

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