how to display only numbers on a form field and stop other inputs using core javascript?

Question

填写表单域时，只应将数字作为输入并显示在表单域上。当填写其他字符如'a'时，它们不显示在表单域上。只能看到以前给出的数字。应该使用core来完成javascript。

Answer 1

http://www.w3schools.com/html/tryit.asp?filename=tryhtml_input_number

<input type="number">

That should be what you need.

Edit : After seeing your comment: This is not your solution, because you want a javascript solution. This should have been in your question, because it is essential to answering the question.

Answer 2

Take a look at this

How To Only Allow Alpha Numeric Chars With JavaScript

and try to replace the regexp with if(!/^[0-9]+$/.test(name)) .