$string = "😃 hello world 🙃";

preg_match('/([0-9#][x{20E3}])|[x{00ae}x{00a9}x{203C}x{2047}x{2048}x{2049}x{3030}x{303D}x{2139}x{2122}x{3297}x{3299}][x{FE00}-x{FEFF}]?|[x{2190}-x{21FF}][x{FE00}-x{FEFF}]?|[x{2300}-x{23FF}][x{FE00}-x{FEFF}]?|[x{2460}-x{24FF}][x{FE00}-x{FEFF}]?|[x{25A0}-x{25FF}][x{FE00}-x{FEFF}]?|[x{2600}-x{27BF}][x{FE00}-x{FEFF}]?|[x{2900}-x{297F}][x{FE00}-x{FEFF}]?|[x{2B00}-x{2BF0}][x{FE00}-x{FEFF}]?|[x{1F000}-x{1F6FF}][x{FE00}-x{FEFF}]?/u', $string, $emojis);

$emojis =  ["😃", "🙃"];

$emojis = ["😃"]