How can I solve isset () problems?

Isset () is used to check whether the variable is set. I have a question. First of all, if & lt; inputtype = "text" name = & quot; age & quot; & gt; is in the form, I will leave nothing blank, submitted to the background. isset ($ _ REQUEST [& quot; age & quot;]) is also a true isset () question.
Isset () is used to check whether the variable is set.

First, in the form, as shown in figure

This form, even if I do not fill in anything, is submitted to the background and isset ($ _ REQUEST ["age"]) is true .. So what are you actually detecting? Do users create their own parameter access? Reduce unnecessary false requests?

Another is to set a hidden field to check whether the form is submitted. then, the user checks the element and finds The name here can also forge a commit process?

What is the meaning of isset?


------ Solution --------------------
Are you sure you want to check whether you have entered anything?

Use the empty () function to determine whether there is any content.

Another is to set a hidden field to check whether the form is submitted. then, the user checks the element and finds The name here can also forge a commit process?


At this time, you need to verify the submitted name data.
Is the simplest verification code/token/encryption acceptable?