Javascript developers are faced with this question more often than not and can’t answer it. In this article, I’ll explain the differences between each of them.

What is “=”?

It is called an assignment operator because it is used to assign a value to a variable. That’s easy to remember.

It’s an assignment operator because it is used to assign/give a value to a variable.

“=” example

Let’s create a variable, x. If we want to give x a value of 10, we would do the following:

let x = 10; That’s it!

Let’s try to assign a value y to the x variable we created above:

let y = x;

The output is 10.

It’s as easy as that!

What is “==”?

1. This is the equality operator. It determines whether two operands are equal, and yields a Boolean result.

2. It tries to convert operands of different types, unlike the strict equality operator (===). After converting the arguments to numbers, the equality operator evaluates them.

“==” example

Take a look at the following example:

console.log("4" == 4);

This returns true because ”4” is converted to a number, making it,

console.log(4 == 4);, which is true.

Examine the following and without scrolling, identify which is true and false:

1. console.log("1" == 1);
2. console.log("0" == 0);
3. console.log(1 == 1);
4. console.log(0 == false);
5. console.log("NaN" == NaN);
6. console.log(NaN == NaN);

Here are the answers:

1. True
2. True
3. True
4. True => The string zero "0" is converted to the Number data type, and the boolean false is converted to the Number data type.
5. False
6. False

What is “===”?

This is the *strict equality operator.* Similar to the equality operator, it checks whether two operands are equal and yields a Boolean result. It does not convert the data types of operands, therefore returns false for values that are not of a similar data type.

Note:

If operand(s):

• are different types => return false

• are both objects => return true (only if both operands are objects and both refer to the same object)

• are null or undefined => return true

• is either NaN => return false

“===” example.

Differences between =, == & ===.

Parameters	=	==	===
1. Name	Assignment operator	Equality operator	Strict equality operator
2. Function	Assigns a value to a variable.	Checks if two operands are equal, but ignore the data type of the variable.	Checks if two operands are equal, but checks the data type of the variable.
3. Return Value	It doesn’t return true or false	Returns true if the two operands are equal, and false if they are not.	Returns true only if data types and operands are equal.

Glossary:

1. Variable:

It is the name of a storage location. It can also be defined as a container for storing values. For example,

x = 5;

x is the variable.

2. Operand:

This is something that is operated on (such as a quantity or data). For example,

5 == 5;

5 is the operand.

3. Boolean:

It represents one of two values: true or false.

Thanks for reading!

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Ciao!