A simple summary of the question about this point in JS

1: Under global scope the This object points to the Window object

For example:

The results are as follows:

2: Under Function scope

In non-strict mode: The point of this is still the Window object

For example:

The results are as follows:

In strict mode:

The point of this is undefined

For example:

The results are as follows:

So inside the function, in strict mode, this point or value is undefined

3: Inside the object

The point of this is the current object

For example:

The results are as follows:

There is a classic question about this point:

Please see:

In non-strict mode, the results are as follows:

If in strict mode, for example:

The results are as follows:

So how do you get the function fn to use the current obj object, the analogy is to output the value of name in FN, how to write?

The first method:

The second solution: (using the arrow function can be very good solution)

A simple summary of the question about this point in JS