JavaScript calls ajax to obtain text file content implementation code_javascript skills

I’ve written a lot about JQuery in the past few years, but I haven’t written traditional JavaScript for a long time, and have forgotten many things. How many people still remember that to implement ajax operations in JavaScript, you need to use the XMLHttpRequest object. In fact, the essence of jquery’s ajax is also this. Okay , today I will take some time to demonstrate how to use traditional javascript to obtain text content and display it on the page. Not much nonsense, just enter the code. The comments are very detailed, everyone should be able to understand: