Operators in Dart
Every expression is composed of operators and operands. Consider the equation “3 + 3”. Here “+” is an operator, and “3,3” are operands.
In this chapter, we will discuss the operators that are available in Dart.
- Arithmetic Operators
- Equality and Relational Operators
- Type test Operators
- Bitwise Operators
- Assignment Operators
- Logical Operators
Arithmetic Operators
The arithmetic operators in the Dart programming language are:
- +(Addition)
- -(Subtraction)
- %(Modulo)
- *(Multiplication)
- /(Division)
- ++(Increment)
- –(Decrement)
- ~/(Divide,return an int value)
Example:
void main() {
int num1 = 10;
int num2 = 3;
print("Addition: ${num1 + num2}");
print("Subtraction: ${num1 - num2}");
print("Multiplication: ${num1 * num2}");
print("Division: ${num1 / num2}");
print("Modulus: ${num1 % num2}");
}
Equality and Relational Operators
Relational Operators test or define the kind of relationship between two entities.
| Operator | Description | Example |
| > | Greater than | (A > B) is False |
| < | Lesser than | (A < B) is True |
| >= | Greater than or equal to | (A >= B) is False |
| <= | Lesser than or equal to | (A <= B) is True |
| == | Equality | (A==B) is False |
| != | Not equal | (A!=B) is True |
Example:
void main() {
int num1 = 10;
int num2 = 3;
print("num1 == num2: ${num1 == num2}");
print("num1 != num2: ${num1 != num2}");
print("num1 > num2: ${num1 > num2}");
print("num1 < num2: ${num1 < num2}");
print("num1 >= num2: ${num1 >= num2}");
print("num1 <= num2: ${num1 <= num2}");
}
Type test Operators
These operators are handy for checking types at runtime.
| Operator | Meaning |
| is | True if the object has the specified type |
| is! | False if the object has the specified type |
Example:
void main() {
var num1 = 10;
if (num1 is int) {
print("num1 is an integer");
}
if (num1 is! double) {
print("num1 is not a double");
}
}
Bitwise Operators
The following table lists the bitwise operators available in Dart and their roles −
| Operator | Description | Example |
| Bitwise AND | a & b | Returns a one in each bit position for which the corresponding bits of both operands are ones. |
| Bitwise OR | a | b | Returns a one in each bit position for which the corresponding bits of either or both operands are ones. |
| Bitwise XOR | a ^ b | Returns a one in each bit position for which the corresponding bits of either but not both operands are ones. |
| Bitwise NOT | ~ a | Inverts the bits of its operand. |
| Left shift | a ≪ b | Shifts an in binary representation b (< 32) bits to the left, shifting in zeroes from the right. |
| Signpropagating right shift | a ≫ b | Shifts an in binary representation b (< 32) bits to the right, discarding bits shifted off. |
Example:
void main() {
int num1 = 5;
int num2 = 3;
print("Bitwise AND: ${num1 & num2}");
print("Bitwise OR: ${num1 | num2}");
print("Bitwise XOR: ${num1 ^ num2}");
print("Bitwise NOT: ${~num1}");
print("Left shift: ${num1 << 2}");
print("Right shift: ${num1 >> 1}");
}
Assignment Operators
The following table lists the assignment operators available in Dart.
| 1 | =(Simple Assignment )Assigns values from the right side operand to the left side operand Ex:C = A + B will assign the value of A + B into C |
| 2 | ??=Assign the value only if the variable is null |
| 3 | +=(Add and Assignment)It adds the right operand to the left operand and assigns the result to the left operand.Ex: C += A is equivalent to C = C + A |
| 4 | ─=(Subtract and Assignment)It subtracts the right operand from the left operand and assigns the result to the left operand.Ex: C -= A is equivalent to C = C – A |
| 5 | *=(Multiply and Assignment)It multiplies the right operand with the left operand and assigns the result to the left operand.Ex: C *= A is equivalent to C = C * A |
| 6 | /=(Divide and Assignment)It divides the left operand with the right operand and assigns the result to the left operand. |
Example:
void main() {
int a = 5;
int b = 2;
// Assign the value of b to a and increment b by 1
a = b++;
print("a = $a, b = $b"); // Output: a = 2, b = 3
// Assign the value of b to a and decrement b by 1
a = b--;
print("a = $a, b = $b"); // Output: a = 3, b = 2
// Add 2 to a and assign the result to a
a += 2;
print("a = $a"); // Output: a = 5
// Subtract 1 from a and assign the result to a
a -= 1;
print("a = $a"); // Output: a = 4
// Multiply a by 2 and assign the result to a
a *= 2;
print("a = $a"); // Output: a = 8
// Divide a by 2 and assign the result to a
a ~/= 2;
print("a = $a"); // Output: a = 4
// Take the remainder when a is divided by 3 and assign the result to a
a %= 3;
print("a = $a"); // Output: a = 1
// Shift the bits of a one position to the left and assign the result to a
a <<= 1;
print("a = $a"); // Output: a = 2
// Shift the bits of a one position to the right and assign the result to a
a >>= 1;
print("a = $a"); // Output: a = 1
// Bitwise AND of a and 3, and assign the result to a
a &= 3;
print("a = $a"); // Output: a = 1
// Bitwise OR of a and 2, and assign the result to a
a |= 2;
print("a = $a"); // Output: a = 3
// Bitwise XOR of a and 3, and assign the result to a
a ^= 3;
print("a = $a"); // Output: a = 0
}
Logical Operators
Logical operators are used to combining two or more conditions.
| Operator | Description | Example |
| && | And − The operator returns true only if all the expressions specified return true | (A > 10 && B > 10) is False. |
| || | OR − The operator returns true if at least one of the expressions specified return true | (A > 10 || B > 10) is True. |
| ! | NOT − The operator returns the inverse of the expression’s result. For E.g.: !(7>5) returns false | !(A > 10) is True. |
Example:
void main() {
bool a = true;
bool b = false;
// Logical AND operator
print(a && b); // Output: false
// Logical OR operator
print(a || b); // Output: true
// Logical NOT operator
print(!a); // Output: false
}
Conditional Expressions
Dart has two operators that let you evaluate expressions that might otherwise require if-else statements −
condition? expr1 : expr2
If the condition is true, then the expression evaluates expr1 (and returns its value); otherwise, it evaluates and returns the value of expr2.
Example:
void main() {
int x = 10;
int y = 20;
// using ternary operator
int result1 = x > y ? x : y;
print("Result 1: $result1");
// using if-else statement
int result2;
if (x > y) {
result2 = x;
} else {
result2 = y;
}
print("Result 2: $result2");
// using null-aware operator
String name;
String displayName = name ?? "User";
print("Display Name: $displayName");
}
Output:
Result 1: 20
Result 2: 20
Display Name: User