AND/OR comparisons starting from null, true, or false..? - php

Question

I want to loop through a set of conditions, returning true only if every condition is met, collecting reasons along the way if not.
<?php
$dataval = 0;
$tests = [
[1,0,0,4,5],
[0,0,0,0,0]
];
foreach($tests as $condition) {
$retval = null;
$reasons = [];
foreach($condition as $item){
if($item == $dataval){
$retval == $retval && true;
} else {
$retval == $retval && false;
$reasons[] = "Failed to match " . $dataval . " to " . $item;
}
}
if($retval === true){
echo "All conditions met<br>";
} else {
echo "NOT all conditions met<br>";
}
echo "<pre>" . print_r($reasons, 1) . "</pre>";
}
?>
OUTPUT
NOT all conditions met
Array
(
[0] => Failed to match 0 to 1
[1] => Failed to match 0 to 4
[2] => Failed to match 0 to 5
)
NOT all conditions met
Array
(
)
No matter what the initial value of $retval, one or both tests is going to fail. If the initial value is true, both tests return true (which is incorrect); if false or null, then both return false (which is also incorrect).
Yes, I could break on the first false, but why the test failed is important, and it could fail for more than one reason so I shouldn't just break out of the loop as soon as the first failure is caught.
Is there a way to do this without adding another variable to tally up the hits and misses?

Answer 1

You need to initialize $retval to true. When you get a mismatch, set it to false and push the error onto the $reason array.
But don't really need the $retval variable. Just check if the array is empty.
foreach($tests as $condition) {
$reasons = [];
foreach($condition as $item){
if($item != $dataval) {
$reasons[] = "Failed to match " . $dataval . " to " . $item;
}
}
if(empty($reasons)){
echo "All conditions met<br>";
} else {
echo "NOT all conditions met<br>";
echo "<pre>" . print_r($reasons, 1) . "</pre>";
}
}