Using the setInterval () function in JavaScript to implement simple round-robin operations _ javascript skills

This article mainly introduces how to use the setInterval () function in JavaScript to implement simple round-robin operations. it analyzes the principle of round-robin operations and javascript implementation skills in the form of examples, for more information about how to use the setInterval () function to perform simple round robin, see the example in this article. Share it with you for your reference. The specific analysis is as follows:

Polling is a way for the CPU to decide how to provide peripheral device services, also known as Programmed I/O ). The concept of the round-robin method is that the CPU regularly sends a query, asking each peripheral device in sequence whether or not they need the service. once the service is completed, it then asks the next peripheral device and continues to repeat it. The polling method is easy to implement, but inefficient.

When using the setInterval function in JavaScript for simple round robin operations, you can determine a parameter value at any time, but you do not need to refresh the page, that is, you do not need to add a header to the page To refresh the page.

I. basic objectives

You do not need the onChange () function to directly use the setInterval function for simple round-robin operations. you can read the content in the text box every 0.5 seconds.

In fact, the principle is the same as that of the JavaScript clock. it takes the current time every second and then updates the text content once.

II. Production process

The code is as follows:

The code is as follows:

Polling