How does jquery realize that the content of the input box cannot be empty?

This article Xiaobian introduces in detail for you "jquery how to achieve the input box content can not be empty", the content is detailed, the steps are clear, the details are handled properly, I hope this "jquery how to achieve the input box content can not be empty" article can help you solve your doubts, the following follow the editor's ideas slowly in-depth, together to learn new knowledge.

Implementation method: 1, use blur () to add a loss of focus event to the input box, and set the event handler function; 2, in the function, use val () to get the contents of the input box, and use the "content = =" statement to determine whether the content of the input box is empty; 3, if it is empty, use the "alert (" input box cannot be empty ");" statement to prompt.

The operating environment of this tutorial: windows7 system, jquery1.10.2 version, Dell G3 computer.

Jquery implements the function that the content of the input box cannot be empty.

The idea of realization is:

When the input box loses focus, get the contents of the input box

Determine whether the input box content is empty, if it is empty, pop up the warning box, remind the content can not be empty

Implementation method:

Use the blur () method to add a loss of focus event to the input box and set the event handler

In the handler function, use val () to get the contents of the input box

Determine whether the content of the input box is an empty character

If so, alert () prompts.

Implementation example:

$(document) .ready (function () {$("input") .blur (function () {var tweets $("input"). Val ()) If (tweak = ") {alert (" input box cannot be empty ");});})

Read this, the "jquery how to achieve the input box content can not be empty" article has been introduced, want to master the knowledge of this article also need to practice and use in order to understand, if you want to know more about the article, welcome to follow the industry information channel.