There are several main reasons for the confusion of this pointing in j**ascript:
The way the function is called is different: the way the function is called in j**ascript determines the point of this. Common function calls include function calls, method calls, constructor calls, and arrow function calls. Different ways of calling this will cause this to point to different objects, which can easily cause confusion. Lost bindings: This inside the function can lose bindings when passed as a standalone variable, or as a function to other functions. This means that this in the function no longer points to the original object, but to a global object (usually a window object in a browser environment) or undefined (in strict mode). Nested functions: When a function is nested inside other functions, this in a nested function will often be different from this in an external function. This can lead to confusion in pointing to this, especially if there are multiple layers of nesting. Use apply, call, or bind methods: apply, call, and bind are methods of this in j**ascript that are used to explicitly specify functions. If these methods are used incorrectly, such as passing the wrong context object, this will result in this pointing to the wrong point. Arrow function: The arrow function has a lexically scoped this binding, which captures the this value of the context in which it is located, rather than dynamically binding this. Therefore, when you use this in an arrow function, it points to the context in which the arrow function was declared, not when it was called. To avoid this pointing confusing problem, you can do the following:
Using the arrow function, make sure this always points to the desired context. When calling a function, make sure that the context object of the function is set correctly, and you can use the bind, call, or apply methods. Use strict mode to avoid this inside the function being bound to a global object by default. In nested functions, use an arrow function or explicitly save the value of this for an external function to avoid pointing this to the inner function incorrectly. Understanding and correctly handling this is an important part of j**ascript development, as it helps us avoid many common mistakes and confusion.