Dart Programming Language: Understanding Variables, Keywords, and Operators

Introduction to Dart Programming Language:

Dart is a modern, object-oriented programming language that is designed to be easy to learn and use. Developed by Google, Dart is used to build high-performance, scalable web and mobile applications. In this blog post, we will start by discussing some basic syntax rules of Dart, including its case-sensitivity, handling of whitespace and line breaks, and the use of semicolons and comments. We will then move on to explore some of the key features of the language, including variables, data types, and operators. So, let's get started!

• Dart is Case-sensitive: This means that Dart differentiates between uppercase and lowercase characters.
• Whitespace and Line Breaks: Dart ignores spaces, tabs, and newlines that appear in programs.
• Statements end with a Semicolon: Each line of instruction is called a statement. Each dart statement must end with a semicolon.
• Comments in Dart: Single-line comments ( // ) Multi-line comments (/* */).

Dart Keywords:

In Dart, keywords are reserved words that have a specific meaning and purpose within the language. These keywords cannot be used as identifiers (such as variable names, function names, or class names) in a Dart program. Some Examples are:

Var :

Var is used to declare variables in Dart. It is a type inference keyword that automatically infers the type of the variable based on its value.

var myVar = 'Hello, World!'; // type of myVar is String

final: 

final is used to declare a variable that can only be assigned once. It is similar to const, but its value can be computed at runtime.

final int myNumber = 42;

const:

const is used to declare a compile-time constant. Its value must be known at compile-time and cannot be changed.

const pi = 3.14;

Dart Variable:

In Dart, a variable is a named storage location in memory that stores a value. Variables are used to store data that can be changed or modified during program execution.

To create a variable in Dart, you use the var keyword, followed by the variable name, and an optional initialization value. Here's an example:

var message = "Hello, world!";

In this example, the var keyword is used to declare a variable named message that is initialized with the string value "Hello, world!".

Dart supports different types of variables, including:

• int: integers (whole numbers)

• double: floating-point numbers with decimal point

• bool: boolean values (true or false)

• String: strings of text

• dynamic: a type that can represent any value at runtime

• To declare a variable with a specific type, you can use the type name instead of var. 

For example:

int age = 25; double weight = 70.5; bool isStudent = true; String name = "Alice";

Operators in Dart:

Dart has a variety of operators, which are special symbols or keywords that perform specific operations on one or more values. Some of the most common operators in Dart include:

Arithmetic operators:

These operators are used for basic arithmetic operations, such as addition (+), subtraction (-), multiplication (*), division (/), and modulus (%).

int x = 5; int y = 3; int result = x + y; // addition result = x - y;     // subtraction result = x * y;     // multiplication result = x ~/ y;    // integer division result = x % y;     // modulo result = -x;        // negation result = ++x;       // increment result = --x;       // decrement

Assignment operators:

These operators are used to assign a value to a variable, while also performing an operation. For example, += adds a value to the current value of a variable, and assigns the result to the variable.

Relational operators:

These operators are used to compare two values and return a boolean value (true or false). Common comparison operators include == (equal to), != (not equal to), < (less than), > (greater than), <= (less than or equal to), and >= (greater than or equal to).

int x = 5; int y = 3; bool result = x > y;  // greater than result = x < y;       // less than result = x >= y;      // greater than or equal to result = x <= y;      // less than or equal to result = x == y;      // equal to result = x != y;      // not equal to

Logical operators:

These operators are used to combine or negate boolean values. The && operator represents logical AND, the || operator represents logical OR, and the ! operator represents logical NOT.

bool a = true; bool b = false; bool result = a && b; // logical AND result = a || b;      // logical OR result = !a;          // logical NOT

Bitwise operators:

These operators are used to manipulate the individual bits of a binary number. Common bitwise operators include & (bitwise AND), | (bitwise OR), ^ (bitwise XOR), << (left shift), and >> (right shift).

int x = 5;    // 101 in binary int y = 3;    // 011 in binary int result = x & y;   // bitwise AND (001) result = x | y;       // bitwise OR (111) result = x ^ y;       // bitwise XOR (110) result = ~x;          // bitwise NOT (010) result = x << 1;      // left shift (010) result = y >> 1;      // right shift (001)

Conditional operator:

This operator is a shorthand for an if-else statement. It allows you to evaluate a boolean expression and return one value if the expression is true, and another value if the expression is false. The syntax for the conditional operator is condition ? value1 : value2.

Type test operator:

This operator is used to check the type of an object at runtime. The is operator returns true if an object is an instance of a specified type, while the as operator is used for type casting.

Cascade notation:

This operator allows you to chain together multiple method calls or property accesses on the same object. It is represented by the .. operator.

These are just a few examples of the operators available in Dart. By using these operators, you can perform a wide range of operations on values, variables, and objects in your Dart programs.

I hope you enjoyed this blog post about the Dart programming language. If you have any questions or comments, please feel free to leave them below. You can follow my github https://github.com/amermahbub for code . Thanks for reading!