Operators in Dart

Here's the Part 1 of this tutorial series in case you've missed it. We discussed the primitive data types and the structure of Dart programs there.

Let us now go ahead and have a look at the various operators available in Dart.

Operators are special symbols which are used to perform operations to compare or manipulate data. eg, +, <, = etc

Types of operators in Dart

Arithmetic Operators
Equality and Relational Operators
Type Test Operators
Assignment Operators
Logical Operators
Bitwise and Shift Operators

Arithmetic Operators

These operators are used to do mathematical operations like addition, subtraction etc Here's the list of arithmatic operators supported by Dart:

+ addition
- Subtraction
* multiplication
- reverse the sign of expression
/division
~/ integer division
% modulo operation

main() {
  var operand1 = 20;
  var operand2 = 5;

  print(operand1 + operand2);
  print(operand1 - operand2);
  print(- operand1);
  print(operand1 * operand2);
  print(operand1 / operand2);
  print(operand1 ~/ operand2);
  print(operand1 % operand2);
}

Apart from that, like C, Dart also supports prefix and postfix operations:

++var -> var = var + 1
var++ -> var = var + 1
--var -> var = var - 1:
var-- -> var = var - 1

Although both var++ and ++var increment the variable they are applied to, the result returned by var++ is the value of the variable before incrementing, whereas the result returned by ++var is the value of the variable after the increment is applied.

We can see that in the snippet below. The same also applies to --var and var--.

main() {
  var n1 = 5;

  print(++n1); // prints 6
  print(n1++); // prints 6 
  print(n1);   // prints 7

  print(--n1); // prints 6
  print(n1--); // prints 6
  print(n1);   // prints 5
}

Relational operators

Relational operators compare value of two number type operands and returns a boolean value.

main() {
  var operand1 = 50;
  var operand2 = 27;

  print(operand1 > operand2);    // prints true
  print(operand1 < operand2);    // prints false
  print(operand1 >= operand2);   // prints true
  print(operand1 <= operand2);   // prints false
  print(operand1 == operand2);   // prints false
  print(operand1 != operand2);   // prints true
}

Type Test operators

Type test operators can be used to check object type at runtime.

main() {
  double type1 = 25.0;
  int type2 = 58;
  String type3 = "Dart Lesson";
  bool type4 = true;

  print(type1 is int);      // prints false
  print(type2 is int);      // prints true
  print(type3 is String);   // prints true
  print(type4 is double);   // prints false
  print(type4 is! double);  // prints true
}

Assignment operator

Assignment operators are used to assign value to a variable. Dart also supports compound assignment operator eg +=, -=, *= etc A += B is equivalent to A = A + B. Let us see a sample usage

main() {
  var A = 10;
  var B = 7;

  A += B;
  print(A);  //prints 17

  A *= B;
  print(A);  //prints 119

  A ~/= B;
  print(A);  //prints 17
}

Logical Operators

Logical operators are used to perform logical AND OR or NOT NOT here is a unary operator.

main() {
  var A = true;
  var B = false;
  var expr = A && B; //false

  print(!A); // !true --> false
  print(!B); // !false --> true
  print(true || expr); // true || expr --> true
  print(false || expr); // false || expr --> expr
  print(true && expr); // true && expr --> expr
  print(false && expr); // false && expr --> false
}

Bitwise and Shift Operators

Bitwise and shift operators perform operations on individual bits of a integer. These are the bitwise operators supported:

& bitwise AND
| bitwise OR
^ bitwise XOR
~ bitwise NOT

And these are the supported shift operators

>> bitwise right shift
<< bitwise left shift

main() {
  var A = 10;
  var B = 20;

  print(~A); // A complement
  print(~B); // B complement
  print(A & B); // A AND B
  print(A | B); // A OR B
  print(A ^ B); // A XOR B
  print(B << 2); // B Shift Left by 2 bits
  print(A >> 2); // A Shift Right by 2 bits
}

That's it for now

Now that we have familiarized ourselves with the different operators Dart provides, let's wrap up our discussion. You can practice your Dart skills on Dartpad which is an online Dart editor.

Next part of this tutorial will start exploring the various collections that we have in Dart so follow my blog to stay updated.

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Happy Coding. Cheers 🍻