<html lang="ko">
<head>
<meta charset="UTF-8">
<title>PHP Built In Function</title>
</head>
<body>
echo strstr("ABCabcDEFabc", "abc")."<br>"; // abcDEFabc
echo strrchr("ABCabcDEFabc", "abc")."<br>"; // abc
echo stristr("ABCabcDEFabc", "abc"); // ABCabcDEFabc
</body>
</html>