IMO, blindly using ===, without trying to understand how type conversion works doesn't make much sense.

The primary fear about the Equals operator == is that the comparison rules depending on the types compared can make the operator non-transitive, for example, if:

A == B AND

B == C

Doesn't really guarantees that:

A == C

For example:

'0' == 0;   // true

 0  == '';  // true

'0' == '';  // false

The Strict Equals operator === is not really necessary when you compare values of the same type, the most common example:

if (typeof foo == function) {

  //..

}

We compare the result of the typeof operator, which is always a string, with a string literal...

Or when you know the type coercion rules, for example, check if something is null or undefinedsomething:

if (foo == null) {

  // foo is null or undefined

}



// Vs. the following non-sense version:



if (foo === null || typeof foo === undefined) {

  // foo is null or undefined

}