JavaScript Operators.

An Expression is a special kind of statement that evaluates to a value. Every expression is composed of -

• Operands: Represents the data.

• Operator: Defines how the operands will be processed to produce a value.

Consider the following expressions 2+3. Here in the expression, 2 and 3 are operands and the symbol + (plus) is the operator. JavaScript supports the following types of operators.

Arithmetic Operators

Relational Operators Relational Operators test or define the kind of relationship between two entities. Relational Operators return a boolean value, i.e true or false.

Assume the value of A is 10 and B is 20.

Logical Operators

Logical operators are used to combine two or more conditions. Logical operators, too return a Boolean Value. Assume the value of variable A is 10 and B is 20.

Bitwise Operators

JavaScript supports the following bitwise operators. The following table summarizes JavaScript's bitwise operators.

Assignment Operators

The following table summarizes assignment operators.

Note- The same logic applies to bitwise operators, so they will become <<=, >>=,>>=, &=, |= and ^=.

Miscellaneous Operators

Following are some of the miscellaneous operators.

The negation operator(-)

Changes the sign of a value. The following program is an example of the same.

var x = 4
var y = -x;
console.log("value of x:  ",x); //outputs 4
console.log("value of y:  ",y); //outputs -4

The following output is displayed on successful execution of the above program.

value of x:  4
value of y:  -4

String operators: Concatenation operator(+)

The + operator when applied to strings appends the second string to the first. The following program help to understand this concept.

var msg = "hello"+"world"
console.log(msg)

The following output is displayed on successful execution of the above program.

helloworld

The concatenation operation doesn't add a space between the strings. Multiple strings can be concatenated in a single statement.

Conditional Operator (?)

This operator is used to represent a conditional expression. The conditional operator is also sometimes referred to as the ternary operator. Following is the syntax

test ? expr1 : expr2

where, Test - refers to the conditional statement.

expr1 - value returned if the condition is true.

expr2 - value returned if the condition is false.

Example:

var num = -2
var result = num >
0 ?"positive" : "non-positive"
console.log(result)

Line 2 checks whether the value in the variable num is greater than zero. if num is set to a value greater than zero, it returns the string "positive" else a "non-positive" string is returned.

The following output is displayed on successful execution of the above program.

non-positive

Type Operators

typeof operator

It is a unary operator. This operator returns the data type of the operand. The following table lists the data types and the values returned by the typeof operator in JavaScript.

The following example code displays the number as the output.

var num = 12
console.log(typeof num); //output: number

The following output is displayed on successful execution of the above code.

number