Operator Types

Unary

A unary operator requires a single operand, either before or after the operator, following this format:

operand operator
operator operand

For example, in the expression a++, ++ is a unary operator.

Binary

A binary operator requires two operands, one before the operator and one after the operator, following this format:

operand1 operator operand2

For example, in the expression a + b = c, + is a binary operator.

Ternary

There is one ternary operator, the conditional operator. For example, in the expression a ? b : c, the use of ? and : in this manner constitutes the ternary operator. We'll discuss this operator more in the Conditional Statements tutorial.

Arithmetic Operators

An arithmetic operator takes numeric values (either literals or variables) as its operands and returns a single numeric value. The standard arithmetic operators are addition (+), subtraction (-), multiplication (*), and division (/). Other arithmetic operators are remainder (%), unary negation (-), unary plus (+), increment (++), decrement (--), and exponentiation (**).

1. Addition (+)

We use this operator in the form operand1 + operand_2. For example:

2 + 3 // evaluates to 5
4 + 10 // evaluates to 14

2. Subtraction (-)

We use this operator in the form operand1 - operand2. For example:

3 - 2 // evaluates to 1
4 - 10 // evaluates to -6

3. Multiplication (*)

We use this operator in the form operand1 * operand2. For example:

3 * 2 // evaluates to 6
4 * 10 // evaluates to 40

4. Division (/)

We use this operator in the form operand1 / operand2. For example:

6 / 3 // evaluates to 2
3 / 2 // evaluates to 1.5
4 / 10 // evaluates to 0.4

5. Remainder (%)

We use this operator in the form operand1 % operand2. For example:

6 % 3 // evaluates to 0
3 % 2 // evaluates to 1
4 % 10 // evaluates to 4

6. Exponentiation (**)

We use this operator in the form operand1 ** operand2. This operator is a part of ECMAScript2016 feature set. For example:

2 ** 3 // evaluates to 8
3 ** 2 // evaluates to 9
5 ** 4 // evaluates to 625

7. Unary Negation (-)

We use this operator in the form -operand. For example:

-4 // evaluates to -4
-(-5) // evaluates to 5 (not --5)

8. Unary Plus (+)

We use this operator in the form +operand. For example:

+4 // evaluates to 4
+(-4) // evaluates to -4

9. Increment (++)

We use this operator in the prefix and postfix forms, forms ++operand and operand++. The prefix form, ++operand, increments the operand by and then returns the value of the operand. The postfix form, operand++, returns the value of the operand and then increments the operand's value by . For example:

process.stdin.on('data', function (data) {
    main(+(data));
});
/**** Ignore above this line. ****/
function main(input) {
    var a = input;
    // Print the value of 'a' and the preincremented value of 'a':
    console.log("a(" + a + "), ++a(" + ++a + ")");
    // Assign the current value of 'a' to 'b' and then postincrement 'a':
    var b = a++;
    // Print the values of 'a' once and 'b' twice, then postincrement the 2nd 'b':
    console.log("a(" + a + "), b(" + b + "), b++(" + b++ + ")");
    // Print the final values of 'a' and 'b':
    console.log("a(" + a + "), b(" + b + ")");
}

a(4), ++a(5)
a(6), b(5), b++(5)
a(6), b(6)

10. Decrement (--)

We use this operator in the prefix and postfix forms, forms --operand and operand--. The prefix form, --operand, decrements the operand by and then returns the value of the operand. The postfix form, operand--, returns the value of the operand and then decrements the operand's value by . For example:

process.stdin.on('data', function (data) {
    main(+(data));
});
/**** Ignore above this line. ****/
function main(input) {
    var a = input;
    // Print the value of 'a' and the predecremented value of 'a':
    console.log("a(" + a + "), --a(" + --a + ")");
    // Assign the current value of 'a' to 'b' and then postdecrement 'a':
    var b = a--;
    // Print the values of 'a' once and 'b' twice, then postdecrement the 2nd 'b':
    console.log("a(" + a + "), b(" + b + "), b--(" + b-- + ")");
    // Print the final values of 'a' and 'b':
    console.log("a(" + a + "), b(" + b + ")");
}

a(4), --a(3)
a(2), b(3), b--(3)
a(2), b(2)