whats the difference between == and === ?

The difference between == and === is that:

1. == converts the variable values to the same type before performing comparison. This is called type coercion.
2. === does not do any type conversion (coercion) and returns true only if both values and types are identical for the two variables being compared.

Example:

1. var one = 1;
2. var one_again = 1;
3. var one_string = "1"; // note: this is string
4. console.log(one == one_again); // true
5. console.log(one === one_again); // true
6. console.log(one == one_string); // true. See below for explanation.
7. console.log(one === one_string); // false. See below for explanation