🚳 Interview Questions: Ajax implementation

#js #interview #ajax

Implement an ajax request function that supports Promise:

🍣Send a request using the XMLHttpRequest object

🍛Initialize the open method, configure the request method and url

🍷Add onload and onerror callback functions

🧉onload determines whether the status code is within the range of 200–300 resolve, otherwise reject

🫘onerror directly reject

🥧After the request is successful, resolve returns response, and after failure, reject reports an error.

🥟Support options to configure request parameters and request body

🍱Returns a Promise object, which can be processed externally using then/catch

Analysis: Promise is used to encapsulate asynchronous ajax requests and achieve a synchronous programming style.