Value Comparison Operators JavaScript Edition

In JavaScript, we have three different value-comparison operators:

What is ( = ) in programming languages?

A single equals symbol (=) is also called an assignment operator.
In simple terms, when I say " a = 5 ", this means that I am putting the value '5' inside the variable ' a '.
Now, when I try to print the value of ' a ', I will get the value ' 5 '.

const a = 5;
console.log(a); // 5

What is ( == ) in programming languages?

The pair of equal signs ( == ) when put together acts as a comparison operator.
This means that it will check for equality in the two values that are placed on both the left and right sides of this operator.

const a = 5;
const b = "5";
console.log(a == b); // true

We can see in the above example that the value of ' a ' is of Integer data type and the value of ' b ' is of String data type and when checking the equality for these values, it results in ' true '.
This means that this equality ( == ) operator does not consider the data type while checking for equality of the values. It only compares the values and if the values are the same, it results in ' true ' or else ' false '.
But before comparison actually takes place, coercion comes into the picture for this operator.
Coercion refers to the automatic conversion of one data type to another.
First, one of the values is converted from one data type into the data type that fits the other value. For eg: The string data type is converted to a Number data type.
After coercion, a comparison between the two values takes place.
For this reason, this operator is also called the loose equality operator.

What is ( === ) in JavaScript?

If we want to compare the data types also while checking for equality in values, then we have the triple equals operator ( === ) aka strict equality operator.
When used, this operator checks for equality in data types of the values along with equality in values.
If the values are of different data types then it will result in ' false '.

const a = 5;
const b = "5";
console.log(a === b) // false

We can see in the above example, even though the values are the same but they have different data types and for this reason, the expression results in ' false '.
Coercion does not take place here.
This operator checks for equality for data type along with the value, this operator is also known as the strict type operator.

This is all about the ( = ) operator in javascript.

JavaScript can be really tricky but I will make sure to explain these complex concepts and topics in as simple way as I possibly can.

DEV Community