Hari 7: String & Manipulasi Data

String Methods Penting

void main() {
  String teks = "  Hello, Flutter World!  ";

  print(teks.trim());                    // "Hello, Flutter World!"
  print(teks.toUpperCase());             // "  HELLO, FLUTTER WORLD!  "
  print(teks.toLowerCase());             // "  hello, flutter world!  "
  print(teks.contains("Flutter"));      // true
  print(teks.replaceAll("Flutter", "Dart")); // "  Hello, Dart World!  "
  print(teks.split(","));               // ["  Hello", " Flutter World!  "]
  print(teks.trim().length);            // 22
  print(teks.trim().startsWith("H"));   // true
  print(teks.trim().substring(0, 5));   // "Hello"
}

StringBuffer untuk String Dinamis

void main() {
  StringBuffer sb = StringBuffer();
  List kata = ["Dart", "adalah", "bahasa", "Flutter"];

  for (String k in kata) {
    sb.write("$k ");
  }
  print(sb.toString().trim()); // "Dart adalah bahasa Flutter"
}

Regular Expression

void main() {
  String email = "user@example.com";
  RegExp emailRegex = RegExp(r"^[\w-]+@[\w-]+\.\w+$");
  print(emailRegex.hasMatch(email)); // true
  print(emailRegex.hasMatch("bukan-email")); // false

  String teks = "Harga: Rp 50000";
  RegExp angka = RegExp(r"\d+");
  Iterable matches = angka.allMatches(teks);
  for (var m in matches) {
    print("Ditemukan: ${m.group(0)}"); // 50000
  }
}