    <!DOCTYPE html>
    <html>
    <head>
      <meta charset="UTF-8">
      <title>String 객체의 메서드 사용하기</title>
      <link rel="stylesheet" href="style_js.css">
    <body>
      <script>
        const s1 = new String("Web ");
        const s2 = "Programming";
        document.write(`s1 = "${s1}"<br>`);
        document.write(`s2 = "${s2}"<hr>`);

        document.write(`s1.charAt(0) : ${s1.charAt(0)}<hr>`);
        document.write(`s1.concat(s2) : ${s1.concat(s2)}<hr>`);
        document.write(`s2.indexOf("i") : ${s2.indexOf("m")}<hr>`);
        document.write(`s2.replace("m", "M") : ${s2.replace("m", "M")}<hr>`);
        document.write(`s2.search("m") : ${s2.search("i")}<hr>`);
        document.write(`s2.split("a") : ${s2.split("a")}<hr>`);
        document.write(`s2.substr(0, 4) : ${s2.substr(0, 4)}<hr>`);
        document.write(`s2.substring(3, 7) : ${s2.substring(3, 7)}<hr>`);
        document.write(`s2.slice(3, -1) : ${s2.slice(3, -1)}<hr>`);
        document.write(`s2.toLowerCase() : ${s2.toLowerCase()}<hr>`);
        document.write(`s2.toUpperCase() : ${s2.toUpperCase()}<hr>`);
        document.write(`s1.trim() : +${s1.trim()}+`);
      </script>
    </body>
    </html>