Operators in JavaScript

• JavaScript operators are symbols or keywords used to perform operations on values and variables.


• They are the building blocks of JavaScript expressions and can manipulate data in various ways.

1. Arithmetic Operator

• Arithmetic operators take numerical values (either literals or variables) as their operands and return a single numerical value.

+= operator

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

let x = 10;

x += 1;

console.log(x); // 11

-= operator

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

let x = 10;

x -= 1;

console.log(x); // 9

(*=) operator

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

let x = 10;

x *= 10;

console.log(x); // 100

/= operator

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

let x = 10;

x /= 2;

console.log(x); // 5

%= operator

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

let x = 5;

x = x % 2;



console.log(x);  // 1

Chaining JavaScript assignment operator

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

let a = 10, b = 20, c = 30;

a = b = c; // all variables are 30

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

let a = 10, b = 20, c = 30;



b = c; // b is 30

a = b; // a is also 30 

3. Comparison / Relational operators

Comparison operators compare two values and return a boolean (true or false). They are useful for making decisions in conditional statements.

See the following example:

console.log("10" == 10); // true

console.log("10" === 10); // false

In the first comparison, since we use the equality operator, JavaScript converts the string into a number and performs the comparison.

However, in the second comparison, we use the strict equal operator (===), JavaScript doesn’t convert the string before comparison, therefore the result is false.