Comparison Operators

They're used to compare 2 operands. Let's look at how they work in JavaScript.

Inequality (!= & !==)

We have seen the NOT(!) operator just now. So, based on that != means NOT-Equal. But why the second operator have 2 equal sign? Let's run the code and understand the difference.

console.log('"10" != 10 = ', "10" != 10);
console.log('"10" !== 10 = ', "10" !== 10);

Lets break down what's happening. So in both the cases, we are comparing "10" which is a string with 10 which is a number.

In the first case, JavaScript converts the number to string. And thus we get false. If you want to know why number got converted to string and not the other way around, then check MDN Docs.

But in the second case, since they are not of the same type, we get true meaning they are not equal.

A general thumb rule, use !==(strict equality) over !=(equality).

With this out of the way, the rest of the example will be self explanatory. Don't forget to try different value in the example.

Equality (== & ===)

Now, this operator is obvious.

NOTE: The single (=) sign is used for Assignment Operator.

console.log('"10" == 10 = ', "10" == 10);
console.log('"10" === 10 = ', "10" === 10);

Less than and Less than or equal (< & <=)

// Comparison Operators
console.log('5 < 5 = ', 5 < 5);
console.log('5 >= 5 = ', 5 <= 5);

Greater than and Greater than or equal > & >=

console.log('5 > 5 = ', 5 > 5);
console.log('5 >= 5 = ', 5 >= 5);