assignment operators supported by javascript

JAVASCRIPT ASSIGNMENT OPERATORS

In this tutorial, you will learn about all the different assignment operators in javascript and how to use them in javascript.

Assignment Operators

In javascript, there are 16 different assignment operators that are used to assign value to the variable. It is shorthand of other operators which is recommended to use.

The assignment operators are used to assign value based on the right operand to its left operand.

The left operand must be a variable while the right operand may be a variable, number, boolean, string, expression, object, or combination of any other.

One of the most basic assignment operators is equal = , which is used to directly assign a value.

Assignment Operators List

Here is the list of all assignment operators in JavaScript:

In the following table if variable a is not defined then assume it to be 10.

Assignment operator

The assignment operator = is the simplest value assigning operator which assigns a given value to a variable.

The assignment operators support chaining, which means you can assign a single value in multiple variables in a single line.

Addition assignment operator

The addition assignment operator += is used to add the value of the right operand to the value of the left operand and assigns the result to the left operand.

On the basis of the data type of variable, the addition assignment operator may add or concatenate the variables.

Subtraction assignment operator

The subtraction assignment operator -= subtracts the value of the right operand from the value of the left operand and assigns the result to the left operand.

If the value can not be subtracted then it results in a NaN .

Multiplication assignment operator

The multiplication assignment operator *= assigns the result to the left operand after multiplying values of the left and right operand.

Division assignment operator

The division assignment operator /= divides the value of the left operand by the value of the right operand and assigns the result to the left operand.

Remainder assignment operator

The remainder assignment operator %= assigns the remainder to the left operand after dividing the value of the left operand by the value of the right operand.

Exponentiation assignment operator

The exponential assignment operator **= assigns the result of exponentiation to the left operand after exponentiating the value of the left operand by the value of the right operand.

Left shift assignment

The left shift assignment operator <<= assigns the result of the left shift to the left operand after shifting the value of the left operand by the value of the right operand.

Right shift assignment

The right shift assignment operator >>= assigns the result of the right shift to the left operand after shifting the value of the left operand by the value of the right operand.

Unsigned right shift assignment

The unsigned right shift assignment operator >>>= assigns the result of the unsigned right shift to the left operand after shifting the value of the left operand by the value of the right operand.

Bitwise AND assignment

The bitwise AND assignment operator &= assigns the result of bitwise AND to the left operand after ANDing the value of the left operand by the value of the right operand.

Bitwise OR assignment

The bitwise OR assignment operator |= assigns the result of bitwise OR to the left operand after ORing the value of left operand by the value of the right operand.

Bitwise XOR assignment

The bitwise XOR assignment operator ^= assigns the result of bitwise XOR to the left operand after XORing the value of the left operand by the value of the right operand.

Logical AND assignment

The logical AND assignment operator &&= assigns value to left operand only when it is truthy .

Note : A truthy value is a value that is considered true when encountered in a boolean context.

Logical OR assignment

The logical OR assignment operator ||= assigns value to left operand only when it is falsy .

Note : A falsy value is a value that is considered false when encountered in a boolean context.

Logical nullish assignment

The logical nullish assignment operator ??= assigns value to left operand only when it is nullish ( null or undefined ).

JS Reference

Html events, html objects, other references, javascript operators reference, javascript operators.

Operators are used to assign values, compare values, perform arithmetic operations, and more.

There are different types of JavaScript operators:

• Arithmetic Operators
• Assignment Operators

Comparison Operators

Logical operators.

• Conditional Operators
• Type Operators

JavaScript Arithmetic Operators

Arithmetic operators are used to perform arithmetic between variables and/or values.

Given that y = 5 , the table below explains the arithmetic operators:

JavaScript Assignment Operators

Assignment operators are used to assign values to JavaScript variables.

Given that x = 10 and y = 5 , the table below explains the assignment operators:

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JavaScript String Operators

The + operator, and the += operator can also be used to concatenate (add) strings.

Given that t1 = "Good " , t2 = "Morning" , and t3 = "" , the table below explains the operators:

Comparison operators are used in logical statements to determine equality or difference between variables or values.

Given that x = 5 , the table below explains the comparison operators:

Conditional (Ternary) Operator

The conditional operator assigns a value to a variable based on a condition.

Logical operators are used to determine the logic between variables or values.

Given that x = 6 and y = 3 , the table below explains the logical operators:

The Nullish Coalescing Operator (??)

The ?? operator returns the first argument if it is not nullish ( null or undefined ).

Otherwise it returns the second argument.

The nullish operator is supported in all browsers since March 2020:

The Optional Chaining Operator (?.)

The ?. operator returns undefined if an object is undefined or null (instead of throwing an error).

The optional chaining operator is supported in all browsers since March 2020:

JavaScript Bitwise Operators

Bit operators work on 32 bits numbers. Any numeric operand in the operation is converted into a 32 bit number. The result is converted back to a JavaScript number.

The table above uses 4 bits unsigned number. Since JavaScript uses 32-bit signed numbers, ~ 5 will not return 10. It will return -6. ~00000000000000000000000000000101 (~5) will return 11111111111111111111111111111010 (-6)

The typeof Operator

The typeof operator returns the type of a variable, object, function or expression:

Please observe:

• The data type of NaN is number
• The data type of an array is object
• The data type of a date is object
• The data type of null is object
• The data type of an undefined variable is undefined

You cannot use typeof to define if a JavaScript object is an array or a date.

Both array and date return object as type.

The delete Operator

The delete operator deletes a property from an object:

The delete operator deletes both the value of the property and the property itself.

After deletion, the property cannot be used before it is added back again.

The delete operator is designed to be used on object properties. It has no effect on variables or functions.

The delete operator should not be used on the properties of any predefined JavaScript objects (Array, Boolean, Date, Function, Math, Number, RegExp, and String).

This can crash your application.

The Spread (...) Operator

The ... operator can be used to expand an iterable into more arguments for function calls:

The in Operator

The in operator returns true if a property is in an object, otherwise false:

Object Example

You cannot use in to check for array content like ("Volvo" in cars).

Array properties can only be index (0,1,2,3...) and length.

See the examples below.

Predefined Objects

The instanceof operator.

The instanceof operator returns true if an object is an instance of a specified object:

The void Operator

The void operator evaluates an expression and returns undefined . This operator is often used to obtain the undefined primitive value, using "void(0)" (useful when evaluating an expression without using the return value).

JavaScript Operator Precedence

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JavaScript Operators

JavaScript Operators are symbols used to perform specific mathematical, comparison, assignment, and logical computations on operands. They are fundamental elements in JavaScript programming, allowing developers to manipulate data and control program flow efficiently. Understanding the different types of operators and how they work is important for writing effective and optimized JavaScript code.

There are various operators supported by JavaScript.

Table of Content

JavaScript Arithmetic Operators

Javascript assignment operators, javascript comparison operators, javascript logical operators, javascript bitwise operators, javascript ternary operators, javascript comma operators, javascript unary operators, javascript relational operators, javascript bigint operators, javascript string operators.

JavaScript Arithmetic Operators perform arithmetic operations: addition (+), subtraction (-), multiplication (*), division (/), modulus (%), and exponentiation (**).

The assignment operation evaluates the assigned value. Chaining the assignment operator is possible in order to assign a single value to multiple variables

Comparison operators are mainly used to perform the logical operations that determine the equality or difference between the values.

JavaScript Logical Operators perform logical operations: AND (&&), OR (||), and NOT (!), evaluating expressions and returning boolean values.

The bitwise operator in JavaScript is used to convert the number to a 32-bit binary number and perform the bitwise operation. The number is converted back to the 64-bit number after the result. 

The ternary operator has three operands. It is the simplified operator of if/else.

Comma Operator (,)  mainly evaluates its operands from left to right sequentially and returns the value of the rightmost operand. 

A unary operation is an operation with only one operand.

JavaScript  Relational operators  are used to compare its operands and determine the relationship between them. They return a Boolean value (true or false) based on the comparison result.

JavaScript BigInt operators support arithmetic operations on BigInt data type, including addition, subtraction, multiplication, division, and exponentiation. Most operators that can be used between numbers can be used between  BigInt values as well.

JavaScript String Operators include concatenation (+) and concatenation assignment (+=), used to join strings or combine strings with other data types.

JavaScript operators are essential tools that empower developers to perform a wide array of operations on data, from simple arithmetic to complex logical decisions. By mastering these operators, you can write more efficient, readable, and maintainable code. Whether you’re performing calculations, making comparisons, assigning values, or manipulating data, understanding how to use JavaScript operators effectively is a fundamental skill for any JavaScript developer. As you continue to build your programming expertise, the versatility and power of operators will become increasingly apparent, enabling you to create more dynamic and robust applications.

JavaScript Operators – FAQs

What are javascript operators.

JavaScript operators are special symbols used to perform operations on operands, which can be values or variables. They allow you to manipulate data and perform computations.

What are the different types of JavaScript operators?

The main types of JavaScript operators include: Arithmetic Operators Assignment Operators Comparison Operators Logical Operators Bitwise Operators String Operators Conditional (Ternary) Operator Type Operators Comma Operator Unary Operators

Can you explain logical operators in JavaScript?

Logical operators are used to combine multiple Boolean expressions: && (Logical AND) || (Logical OR) ! (Logical NOT)

How does the ternary operator work in JavaScript?

The ternary operator is a shorthand for the if-else statement. It takes three operands: condition ? expressionIfTrue : expressionIfFalse;

What does the typeof operator do?

The typeof operator returns the type of a variable as a string. For example, typeof 42 returns “number”.

What is the purpose of the instanceof operator?

The instanceof operator checks if an object is an instance of a specific class or constructor. For example, let date = new Date(); date instanceof Date returns true.

We have a list of JavaScript Operators Reference where you can know more about these operators.

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Home » JavaScript Tutorial » JavaScript Assignment Operators

JavaScript Assignment Operators

Summary : in this tutorial, you will learn how to use JavaScript assignment operators to assign a value to a variable.

Introduction to JavaScript assignment operators

In JavaScript, an assignment operator ( = ) assigns a value to a variable .

Here’s the syntax of the assignment operator:

In this syntax, JavaScript evaluates the expression b first and assigns the result to the variable a .

For example, the following declares the counter variable and initializes its value to zero:

The following example increases the counter variable by one and assigns the result to the counter variable:

When evaluating the second statement, JavaScript evaluates the expression on the right-hand first ( counter + 1 ) and assigns the result to the counter variable. After the second assignment, the counter variable is 1 .

To make the code more concise, you can use the += operator like this:

In this syntax, you don’t have to repeat the counter variable twice in the assignment.

The following table illustrates assignment operators that are shorthand for another operator and the assignment:

+= operator

The following example uses the += operator to add one to variable x :

-= operator

The following example uses the -= operator to minus one from the variable x :

*= operator

The following example uses the *= operator to multiply 10 with the variable x :

/= operator

The following example uses the /= operator to divide x by 2 and assign the result back to x:

%= operator

The following example uses the %= operator to get the remainder of x is divided by 2 and assigns the remainder back to x :

Chaining JavaScript assignment operators

If you want to assign a single value to multiple variables, you can chain the assignment operators. For example:

In this example, JavaScript evaluates from right to left. Therefore, it does the following:

• Use the assignment operator ( = ) to assign a value to a variable.
• Chain the assignment operators if you want to assign a single value to multiple variables.

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• Assignment operators

An assignment operator assigns a value to its left operand based on the value of its right operand.

The basic assignment operator is equal ( = ), which assigns the value of its right operand to its left operand. That is, x = y assigns the value of y to x . The other assignment operators are usually shorthand for standard operations, as shown in the following definitions and examples.

Simple assignment operator which assigns a value to a variable. The assignment operation evaluates to the assigned value. Chaining the assignment operator is possible in order to assign a single value to multiple variables. See the example.

Addition assignment

The addition assignment operator adds the value of the right operand to a variable and assigns the result to the variable. The types of the two operands determine the behavior of the addition assignment operator. Addition or concatenation is possible. See the addition operator for more details.

Subtraction assignment

The subtraction assignment operator subtracts the value of the right operand from a variable and assigns the result to the variable. See the subtraction operator for more details.

Multiplication assignment

The multiplication assignment operator multiplies a variable by the value of the right operand and assigns the result to the variable. See the multiplication operator for more details.

Division assignment

The division assignment operator divides a variable by the value of the right operand and assigns the result to the variable. See the division operator for more details.

Remainder assignment

The remainder assignment operator divides a variable by the value of the right operand and assigns the remainder to the variable. See the remainder operator for more details.

Exponentiation assignment

This is an experimental technology, part of the ECMAScript 2016 (ES7) proposal. Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future version of browsers as the spec changes.

The exponentiation assignment operator evaluates to the result of raising first operand to the power second operand. See the exponentiation operator for more details.

Left shift assignment

The left shift assignment operator moves the specified amount of bits to the left and assigns the result to the variable. See the left shift operator for more details.

Right shift assignment

The right shift assignment operator moves the specified amount of bits to the right and assigns the result to the variable. See the right shift operator for more details.

Unsigned right shift assignment

The unsigned right shift assignment operator moves the specified amount of bits to the right and assigns the result to the variable. See the unsigned right shift operator for more details.

Bitwise AND assignment

The bitwise AND assignment operator uses the binary representation of both operands, does a bitwise AND operation on them and assigns the result to the variable. See the bitwise AND operator for more details.

Bitwise XOR assignment

The bitwise XOR assignment operator uses the binary representation of both operands, does a bitwise XOR operation on them and assigns the result to the variable. See the bitwise XOR operator for more details.

Bitwise OR assignment

The bitwise OR assignment operator uses the binary representation of both operands, does a bitwise OR operation on them and assigns the result to the variable. See the bitwise OR operator for more details.

Left operand with another assignment operator

In unusual situations, the assignment operator (e.g. x += y ) is not identical to the meaning expression (here x = x + y ). When the left operand of an assignment operator itself contains an assignment operator, the left operand is evaluated only once. For example:

Specifications

Browser compatibility.

• Arithmetic operators

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