DartIntro.md

Dart Basics

Here is a basic dart program that covers some basic concepts like variables, functions, conditionals, loops, and classes:

void main() {
  // Variables
  var name = 'Srinivas';
  int age = 20;
  double height = 5.9;
  bool isAdult = age > 18 ? true : false;

  // Print statements
  print('Name: $name');
  print('Age: $age');
  print('Height: $height');

  // Conditional statement
  if (isAdult) {
    print('$name is an adult.');
  } else {
    print('$name is not an adult.');
  }

  // Function call
  greet(name);

  // Loop
  for (int i = 1; i <= 5; i++) {
    print('Loop iteration $i');
    if (i == 3) {
      break;
    }
  }

  // Friends array
  List<String> friends = ['Bhanu', 'Amar', 'Amulya', 'Kiran', 'Sandeep'];

  // Looping through the friends array
  for (String friend in friends) {
    print('Hello, $friend!');
  }

  // Creating an object of the Person class
  Person person = Person(name, age, height);
  person.introduce();

  // Exception handling
  try {
    // Code that may throw an exception
    int result = 10 ~/ 0; // Floor division by zero
    print('Result: $result');
  } catch (e) {
    // Handling the exception
    print('An error occurred: $e');
  }
}

// Function definition
void greet(String name) {
  print('Welcome to SDC, $name!');
}

// Class definition
class Person {
  String name;
  int age;
  double height;
  bool isAdult;

  // Constructor
  Person(this.name, this.age, this.height) : isAdult = age > 18;

  // Method
  void introduce() {
    print(
        'My name is $name, I am $age years old and my height is $height feet.');
  }
}

Explanation:

1. Main Function:

   • Entry point of the Dart program.

2. Variables:

   • var name = 'Srinivas';: String variable for the name.
   • int age = 20;: Integer variable for age.
   • double height = 5.9;: Double variable for height.
   • bool isAdult = age > 18 ? true : false;: Boolean variable using a ternary operator to check if age is greater than 18.

3. Print Statements:

   • print('Name: $name');: Prints the name.
   • print('Age: $age');: Prints the age.
   • print('Height: $height');: Prints the height.

4. Conditional Statement:

   • Checks if isAdult is true.
   • If true, prints that the person is an adult.
   • Otherwise, prints that the person is not an adult.

5. Function Call:

   • Calls the greet function with name as the argument.

6. Loop:

   • for (int i = 1; i <= 5; i++): Loop from 1 to 5.
   • print('Loop iteration $i');: Prints the current iteration.
   • if (i == 3) break;: Breaks the loop if i equals 3.

7. Friends Array:

   • List<String> friends = ['Bhanu', 'Amar', 'Amulya', 'Kiran', 'Sandeep'];: List of friends' names.

8. Looping Through the Friends Array:

   • for (String friend in friends): Iterates over each friend in the array.
   • print('Hello, $friend!');: Prints a greeting for each friend.

9. Object Creation:

   • Creates an object person of the Person class.
   • Calls the introduce method of the Person class.

10. Exception Handling:

    • try: Code that may throw an exception.
    • int result = 10 ~/ 0;: Floor division by zero (will throw an exception).
    • catch (e): Catches the exception and prints an error message.

11. Function Definition:

    • void greet(String name): Function that takes a string parameter.
    • Prints a welcome message with the provided name.

12. Class Definition:

    • class Person: Defines a Person class.
    • Properties: name, age, height, and isAdult.
    • Constructor: Initializes the properties and sets isAdult based on the age.
    • Method: introduce: Prints the person's details.

Output

/> dart run
Name: Srinivas
Age: 20
Height: 5.9
Srinivas is an adult.
Welcome to SDC, Srinivas!
Loop iteration 1
Loop iteration 2
Loop iteration 3
Hello, Bhanu!
Hello, Amar!
Hello, Amulya!
Hello, Kiran!
Hello, Sandeep!
My name is Srinivas, I am 20 years old and my height is 5.9 feet.
An error occurred: Unsupported operation: Infinity

This program provides a basic introduction to Dart's syntax and some fundamental programming concepts. You can run this code in any Dart environment, such as the DartPad online editor (https://dartpad.dev/).

After understanding these basic concepts, you can explore more advanced topics in Dart on Dart's official website (https://dart.dev/language).