The Essential JavaScript Operators

By Richard

Operations

When using an expression like 2 + 3 equals 5, the 2 and the 3 are operands and the + is known as the operator. JavaScript allows you to perform operations on data operands. Here is a list of supported operators:

Assignment Operators
Arithmetic Operators
Unary Operators
Comparison Operators
String Operators
Logical Operators

All of the operators won’t be covered in this one tutorial since all we need are the essentials to get started with programming. Once we’ve reached a certain level of programming I will go into more details on the ones that have been left out.

Assignment Operators

The most basic assignment operator is the = sign which assigns the value on the right operand to the left. The other assignment operators that are listed below are considered shorthand.

var x = 3; // Assigns the value 3 to x
x += 5; // The value of x will be 8
x -= 1; // The value will be 4

If the last two statement above confused you a little, it’s okay. The first statement assigns x the value of 3. On the statement below it we aren’t creating a new variable since there is no var in front of it. What we are doing instead is taking the value of x and adding 5 to it with the += operator which gives you the value of 8 in the end. Finally, the last statement takes the value of x, which is currently 8 and subtracts 1. That leaves x as 7.

Arithmetic Operators

Arithmetic has the basic operators used in JavaScript and are easily recognizable. It’s not just limited to 2 operands, but for example purposes lets stick to simple expressions.

var x = 2 + 5 // Adds 2 numbers which assigns&amp;amp;amp;nbsp;7 to the variable x
var y = 3 * 4 // Multiplies 2 numbers which assigns 12 to the variable y
var z = 7 – 6 // Subtracts 2 numbers which assigns 1 to the variable z
var a = 8 / 2 // Divides 2 numbers which&amp;amp;amp;nbsp;assigns 4 to the variable a

Another operator is known as the modulus which is represented by the % symbol. What it does is divides the two operands and the remainder is the result.

var x = 11 % 5 // x is equal to 1 because the remainder here is 1

Unary Operators

Unary operators only need a single operand, and it can be placed in front or behind the operator. They are pretty straight forward and great to use.
Let’s start by creating a variable with a value of 5.

var x = 5

Typically using the arithmetic operand, to add one you can simply write this:

x = x + 1; // Since x was initially 5 we added one to make it 6

It’s simple and it works! There’s another way of doing it though. An easier and quicker way. This is just a brief introduction and I will go into more detail about it in a later tutorial.

var x = 3;
x = x + 1; // Equals 4
x++; // Equals 5

Since x started out as 3 we then added 1 to it to make it for. Then after that we used the unary operator ++ and added 1 to it again which then leaves x as 5. Now if you want to subtract one all you have to do is use the — operator instead.


x--; // Subtract one from the value of x.

For now if you’re new to JavaScript and are following along I would stick to the more traditional arithmetic operator (+) until I come back to explaining more on the unary operators.

Conclusion

There are a good amount of operators that can be used in JavaScript where I covered just the basic assignment, arithmetic and partially, the unary operator. In the next tutorial we’ll go ahead and look at important conditional statements.

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Operations

Assignment Operators

Arithmetic Operators

Unary Operators

Conclusion

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