I have a one textbox. It name is example.
<input type="text" name="example"/>
I want to check, any data is coming from example or not. I tried use code as below:
<?php
if(empty($_POST["example"]))
{
echo "You need to enter any text to example box.";
}
?>
But this code is printing,when I enter the page is first. I want to see printed data, only when click submit.
check for
if(!isset($_POST["submitButtonName"]))
{
// validation logic here
}
isset is the proper choice here -- empty is only intended to examine a known variable to see if it is "emptyish". According to the docs
The following things are considered to be empty:
"" (an empty string) 0 (0 as an integer) 0.0 (0 as a float) "0" (0 as a string) NULL FALSE array() (an empty array) var $var; (a variable declared, but without a value in a class)
What it doesn't say is how it treats array members that are not defined. A comment on the docs page gives us some insight from testing: http://www.php.net/manual/en/function.empty.php#105722
Note that checking the existence of a subkey of an array when that subkey does not exist but the parent does and is a string will return false for empty.
Whereas isset (docs) is designed to "Determine if a variable is set and is not NULL. " -- exactly what you're after. Thus, your code ends up looking like this:
// check the length, too, to avoid zero-length strings
if(!isset($_POST["example"]) || strlen(trim($_POST["example"])) < 1) {
echo "You need to enter any text to example box.";
} else {
// handle form submission
}
Documentation
PHP isset - http://php.net/manual/en/function.isset.php
PHP empty - http://www.php.net/manual/en/function.empty.php
More reading - http://virendrachandak.wordpress.com/2012/01/21/php-isset-vs-empty-vs-is_null/
<?php
if(isset($_POST['example']) && empty($_POST['example']))
{
echo "You need to enter any text to example box.";
}
?>
0 and "0" are considered empty. You may not want that.if (!empty ($_POST))
{
// Validation logic here
if ((!isset ($_POST ['example'])) || (empty ($_POST ["example"])))
{
echo "You need to enter any text to example box.";
}
}
else
{
// No need to do any validation logic, the form hasn't been submitted yet.
}
Its a better choice to use:
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
if(empty($_POST["example"]))
{
echo "You need to enter any text to example box.";
}
}
This will check if there's a POST on server and then you will have your conditions.
Check $_POST variables first becuase it will be available only when page is submitted.
<?php
if(!empty($_POST)){
if(isset($_POST['example']) && empty($_POST['example'])){
echo "You need to enter any text to example box.";
}
}
?>
Check for the submit button first.
<input type="text" name="example" value="" />
<input type="submit" name="submit" value="submit" />
<?php
if (isset($_POST['submit'])) {
if (empty($_POST['example'])) {
echo "You need to enter any text to example box.";
}
?>
submit button.
