Getting values of only certain input fields?

my_name

I have a script that has something like this in it:

foreach ($_POST as $currentpost) {
	echo $currentpost;
}

This code prints out all POST values. Is there a way I could limit which values the script outputs?

Example: let's say that I had a set of POST fields whose names started with "example," following by a number, as in the following: "example012," "example32," "exampleAB," etc. Could I grab the values of only these POST fields? In other words, if the name of the POST field started with "example," then it would print out the value of the POST field; otherwise, it would be ignored.

Thanks in advance!

laserlight

Use [man]substr/man to check if the starting characters are "example".

That said, you may actually wish to use an array instead, so you just iterate over $_POST['example']

my_name

substr() is cool and all, but what string am I checking in it? Like I said, I'm really not concerned with the actual value of the POST; what I really need to check is the name of it.

laserlight

Check something like this:

substr($currentpost, 0, strlen("example")) == "example"

though you may want to do the strlen() just once.

Still, consider the idea of an array.

my_name

Wouldn't an array be extremely inefficient? I won't know what the names of the POST fields are (except that they start with the word "example"), so what you're suggesting is that I iterate over an array and guess every possible combination of words thereafter? Such as: examplea, exampleb, examplec...exampleaa, exampleab, exampleac? I can't see that working. That'd be like a bruteforce combination guessing game.

As for this:

substr($currentpost, 0, strlen("example")) == "example"

That's going to check the value of the field, not the name, because $currentpost holds the value, not the name.

laserlight

Wouldn't an array be extremely inefficient? I won't know what the names of the POST fields are (except that they start with the word "example"), so what you're suggesting is that I iterate over an array and guess every possible combination of words thereafter?

Suppose you have a set of form input elements:

<input type="text" name="example[]" />
<input type="text" name="example[]" />
<input type="text" name="example[]" />

Now you can iterate over them:

foreach ($_POST['example'] as $value) {
	// ...
}

The form elements might be structured a little differently:

<input type="text" name="example[a]" />
<input type="text" name="example[b]" />
<input type="text" name="example[aa]" />

But now you iterate over them:

foreach ($_POST['example'] as $key => $value) {
	// ...
}

my_name

That may work. Thanks.