Why use === instead of == when comparing a String [duplicate]

Question

When checking for a String value I use '=='. But I have seen instances where '===' is used. For example, instead of

if("true" == "true"){
 alert('true');
}

this is used :

if("true" === "true"){
 alert('true');
}

What is the reasoning behind this ? Both use cases seem to work as expected.

Answer 1

The === operator ensures that not only the values are equal, but the two items being compared are of the same type too; Whereas the == operator only checks that the values of the two items are equal

As @amnotiam mentioned in the comments, you may also want to check out the The Abstract Equality Comparison Algorithm