// Dart语言声明布尔变量 void main() { bool test; test=12 > 5; print(test); }

// Dart语言字符串codeUnitAt()方法 void main() { var res = "Good Day"; print("Code Unit of index 0 (G): ${res.codeUnitAt(0)}");

// Dart语言toString()方法 void main() { int n = 12; var res = n.toString(); print("New String: ${res}");

// Dart语言substring()方法 void main() { String str1 = "Hello World"; print("New String: ${str1.substring(6)}");

//Dart语言字符串split()方法 void main() { String str1 = "Today, is, Thursday"; print("New String: ${str1.split(',')}");

void main() { String str1 = "Hello World"; print("New String: ${str1.replaceAll('World','ALL')}");

void main() { String str1 = "A"; String str2 = "A"; String str3 = "B";

void main() { String str1 = "hello"; String str2 = "hello world"; String str3 = "hello";

void main() { String uStr = "ABC"; String lStr = "hello"; print(uStr.toLowerCase());

void main() { String uStr = "ABC"; String lStr = "hello"; print(uStr.toLowerCase());

void main() { String str = "Hello All"; print("The length of the string is: ${str.length}");

void main() { int n=1+1; String str1 = "The sum of 1 and 1 is ${n}"; print(str1); String str2 = "The sum of 2 and 2 is ${2+2}";

void main() { String str1 = 'this is a single line string'; String str2 = "this is a single line string";

void main() { double n1 = 2.123; var value = n1.truncate(); print("The truncated value of 2.123 = ${value}");

void main() { int n1 = 2; var value = n1.toString(); print( value is String ); }

void main() { double n1 = 2.0; var value = n1.toInt(); print("Output = ${value}"); }

void main() { int n1 = 2; var value = n1.toDouble(); print("Output = ${value}"); }

// Dart语言运行时向映射文字添加值 void main() { var details = {'Usrname':'tom','Password':'pass@123'};

// Dart语言映射文字 void main() { var details = {'Usrname':'tom','Password':'pass@123'};

void main() { List l = [1, 2, 3,4,5,6,7,8,9]; print('The value of list before removing the list element ${l}');

// Dart语言List.removeAt()方法 void main() { List l = [1, 2, 3,4,5,6,7,8,9]; print('The value of list before removing the list element ${l}');

// Dart语言List.remove()方法 void main() { List l = [1, 2, 3,4,5,6,7,8,9]; print('The value of list before removing the list element ${l}');

// Dart语言List.insertAll()方法 void main() { List l = [1,2,3]; l.insertAll(0,[120,130]); print(l);

// Dart语言List.insert()方法 void main() { List l = [1,2,3]; l.insert(0,4); print(l); }

// Dart语言List.addAll()方法 void main() { List l = [1,2,3]; l.addAll([12,13]); print(l); }

// Dart语言插入元素到列表/ void main() { List l = [1,2,3]; l.add(12); print(l); }

// Dart语言List.single方法 void main() { var lst = new List(); lst.add(12); print("The list has only one element: ${lst.single}");

void main() { var lst = new List(); lst.add(12); lst.add(13); print("The list values in reverse order: ${lst.reversed}");

// Dart语言List.last方法 void main() { var lst = new List(); lst.add(12); lst.add(13); print("The last element of the list is: ${lst.last}");

// Dart语言List.length方法 void main() { var lst = new List(); lst.add(12); lst.add(13); print("The length of the list is : ${lst.length}");