String Manipulation and Collections

Importance

String manipulation is essential for processing and formatting text data in programming, such as generating messages, formatting user input, or performing text-based calculations.

Common Operations

• Concatenation: Concatenation combines two or more strings into one. Dart uses the + operator for this.

    void main() {
  String firstName = 'John';
  String lastName = 'Doe';
  
  // Concatenate two strings
  String fullName = firstName + ' ' + lastName;
  
  print('Full Name: $fullName'); // Output: Full Name: John Doe
    }
  

• Interpolation String interpolation allows embedding variables directly within a string. Dart uses $ for simple variables and ${} for expressions.

  void main() {
  String name = 'Alice';
  int age = 30;

  // String interpolation with a variable
  String greeting = 'Hello, $name!';

  // String interpolation with an expression
  String message = 'In 5 years, you will be ${age + 5} years old.';

  print(greeting); // Output: Hello, Alice!
  print(message);  // Output: In 5 years, you will be 35 years old.
  }

• Substring: The substring() method extracts a portion of a string by specifying start and end indices.

  void main() {
    String text = 'Hello, Dart programming!';

    // Extract a substring from index 7 to 11
    String subText = text.substring(7, 11);

    print('Substring: $subText'); // Output: Substring: Dart
  }