PHP IF Statements Error is_string - php

Question

I've been studying PHP using only the internet, so I've been experiencing errors.
<?php
$name = $_POST['name'];
$lg = $_POST['lg'];
if (is_string($name) && is_numeric($lg)) {
header( "Location: portal.php?ejhbusbhdubr=nennuncuiecbdhbcvhebchebcdjebcdsjhbcebhfcvebhdchebhcvhervbhecbvecveh" ) ;
}
if (empty($name) && is_numeric($lg)) {
echo "Please enter your name.";
}
else {
header ("Location: index.php?invalid=true");
}
?>
I'm having problems with the second if statement. What I'm trying to do is that I'm trying to make an error message appear when the $name variable is left empty, and the $lg variable isn't. I think the is_string variable handler's the problem here. Perhaps a string can be empty. But as I said, since I don't have a book, I don't know what to change it too.
In case you still don't get what I mean,
Name: ""
LG: "1234"
I want the above to return as error. Help would be appreciated.

Answer 1

Try to write you condition like this:
if (empty($name) && !empty($lg))

Answer 2

Try it like this, I just moved your if over the first one, and changed it a bit. You have to test if the string is empty before testing, if it is a string. I mean is_string will return true even if the string is empty.
<?php
$name = $_POST['name'];
$lg = $_POST['lg'];
if (empty(trim($name)) && is_numeric($lg)) {
echo "Please enter your name.";
}
elseif(is_numeric($lg)) {
header( "Location: portal.php?ejhbusbhdubr=nennuncuiecbdhbcvhebchebcdjebcdsjhbcebhfcvebhdchebhcvhervbhecbvecveh" ) ;
die();
}
else {
header ("Location: index.php?invalid=true");
die();
}