JavaScript checks whether the textarea value is null and provides corresponding tips _ javascript skills

If no data is input, a prompt is displayed. How can this problem be determined? In the following example, we use JavaScript to determine whether the textarea value is empty. If the user does not enter the data, a prompt is displayed, so how can we determine it? This section describes how to use JavaScript to determine whether the textarea value is null.

The JavaScript function is provided below:

If (document. getElementById ("htmer"). value = '') {alert (" Enter the content! "); Return false ;}

Note that the red part in the above Code is '= '', which is a single quotation mark instead of a double quotation mark, which can reduce unnecessary troubles.