Using empty() to adjust output with multiple variables - php

Question

I have two primary variables that are composed of strings and other variables. I want the two primary variables only to be echo'ed if all the variables that they are comprised of have data.
The two primary variables are $introduction and colortxt.
$introduction is comprised of $finalvehicle3, $bodystyle, $mileage, and $hi.
$colortxt is comprised of $model, $exterior, and $interiorspec.
If any of the secondary variables are empty, I don't want the primary variable to be displayed.
Below is the code I have created that doesn't seem to be working. I have been using empty().
My PHP:
<?php
$finalvehicle3 = "Toyota Camry";
$bodystyle = "sedan";
$mileage = "30,000";
$hi = null;
$model = "Camry";
$exterior = "red";
$interiorspec = "black cloth";
if (empty([$finalvehicle3, $bodystyle, $mileage, $hi]) == true){
$introduction = "";
}
else {
$introduction = "I am pleased to present this ".$finalvehicle3." ".$bodystyle." with ".$mileage." miles.";
}
if (empty([$model, $exterior, $interiorspec]) == true){
$colortxt = "";
}
else {
$colortxt = "This ".$model." is finished in ".$exterior." with a ".$interiorspec. " interior.";
}
echo "<textarea name='' id='' style='width: 565px;' rows='8' cols='60'>";
echo $introduction." ".$colortxt;
echo "</textarea>";
echo "<br><br>";
?>
In this case $introduction should not be displayed as $hi = null

Answer 1

I can't get empty([$finalvehicle3, $bodystyle, $mileage, $hi]) to work.
I was able to use:
if (empty($hi)
|| empty($finalvehicle3)
|| empty($bodystyle)
|| empty($mileage)){
$introduction = "";
}
else {
$introduction = "I am pleased to present this ".$finalvehicle3." ".$bodystyle."
with ".$mileage." miles.";
}
Will that not work?

Answer 2

Check if both variables are not empty echo them out:
if (!empty($introduction) && !empty($colortxt)) {
echo $introduction." ".$colortxt;
}
As a side, while coding style has personal preference, where you set these variables seems awkward as you set them to empty based on a condition, but logically (my logical at least) is to instead preset them to empty and add data if the data exists.
INSTEAD of your code here:
if (empty([$finalvehicle3, $bodystyle, $mileage, $hi]) == true){
$introduction = "";
}
else {
$introduction = "I am pleased to present this ".$finalvehicle3." ".$bodystyle." with ".$mileage." miles.";
}
if (empty([$model, $exterior, $interiorspec]) == true){
$colortxt = "";
}
else {
$colortxt = "This ".$model." is finished in ".$exterior." with a ".$interiorspec. " interior.";
}
Do this:
$introduction = "";
$colortxt = "";
if (!empty([$finalvehicle3, $bodystyle, $mileage, $hi]) == true) {
$introduction = "I am pleased to present this ".$finalvehicle3." ".$bodystyle." with ".$mileage." miles.";
}
if (!empty([$model, $exterior, $interiorspec]) == true) {
$colortxt = "This ".$model." is finished in ".$exterior." with a ".$interiorspec. " interior.";
}
Just looks cleaner to me :)
I'd also not create a new array to check multiple variables, and would do:
if (
!empty($finalvehicle3)
&& !empty($bodystyle)
&& !empty($mileage
&& !empty($hi)
) {

Answer 3

To clarify (not intended to take away from the other answers); only isset() can accept multiple comma-separated values, and not empty().
The manuals state:
on empty():
bool empty ( mixed $var )
on isset()
bool isset ( mixed $var [, mixed $... ] )
Therefore you need to separate and check if each value is empty.
I.e.:
if(empty($var1)) && empty($var2)){}
Or using the || (OR) logical operator depending on what you want to check for; if any or all are empty.
http://php.net/manual/en/language.operators.logical.php
Note:
What you used here:
if (empty([$finalvehicle3, $bodystyle, $mileage, $hi]) == true)
theoretically would be a "false positive".
If anything, you will need to use the == true in a separate statement.
I.e.:
if(empty($var1)) && empty($var2) && $x_var == true){}
However, the first 2 would need the ! negation operator since you're checking if something is true.
I.e.:
if(!empty($var1)) && !empty($var2) && $x_var == true){}