Comparing two arrays in PHP foreach - php

Question

What's the best way to compare both two arrays to each other in a foreach loop ?
I have two arrays, which one holds a boolean values and other one represents the real values.
First one of the arrays is some sort of configuration file where I tell what field is a required one TRUE or an optional FALSE:
$rules = array(
'fieldname1' => TRUE,
'fieldname2' => FALSE,
'fieldname3' => TRUE,
'fieldname4' => TRUE,
'fieldname5' => FALSE,
'fieldname6' => FALSE,
'fieldname7' => TRUE,
'fieldname8' => TRUE
);
And the other array which holds incoming data to be worked out:
$fields = array(
'fieldname1' => 'some value',
'fieldname3' => 'some value',
'fieldname4' => 'some value',
'fieldname7' => 'some value',
'fieldname8' => 'some value'
);
How do I make a check in foreach() loop, so the $fields array is going to compare each of its fieldnameX or (keys/indexes) with the other array named $rules ?
For example: $rules['fieldname1'] is required as it have a bool TRUE. So in foreach($fields as $field), the $field named fieldname1 should not be empty, null or false, if so, show an error.
This is a function I did so far which is not doing exactly what I want:
private function check_field_required_exist( $fields )
{
// Read rules from config to work with them accordingly
$rules = config_item('flow.format')[$fields['format']];
// Run throught the rules
foreach( array_keys($rules) as $field )
{
// Check wheter key existance is failed
if( !array_key_exists($field, $fields) )
{
// Checking failed, terminate the process
die('Required field: "'. $field .'" for requested format: "'.$fields['format'].'" does not exists.');
}
}
// Everything is alright
return TRUE;
}

Answer 1

// Goes through all the rules
foreach($rules as $key => $value)
{
// access all fields that are marked as required i.e key set as TRUE
if ($value)
{
//for those whose value is TRUE, check whether the corresponding field is set or
// whether it is empty (NULL,false)
if(!isset($fields[$key]) || empty($fields[$key]))
{
die('Required field does not exist');
}
}
}

Answer 2

foreach ($fields as $field => $value)
{
if (array_key_exists($field, $rules) && $rules[$field] === true)
{
if (!$value || $value == "" || $value === null)
{
die(); // return false;
}
}
}
return true;

Answer 3

I think that you can play around with the array functions in PHP. First thing I would do is to apply array_filter on your rules array. That way, you will only keep the TRUE values (and their indexes, since array_filter keep the index/value association).
Then I would use array_intersect_key to keep only the fields of interest in your fields var. And again array_filter with a custom callback to perform the verification you want to do.

Answer 4

$requiredField = array();
foreach($rules as $key=>$value) {
if($value == true && (!isset($fields[$key]) || $fields[$key] == "" )) {
$requiredField[] = $key;
}
}
if(count($requiredField) > 0) {
echo implode(',',$requiredField)." Are Required";
die;
}

Answer 5

USING PHP Array Functions:
$rules = array('name' => TRUE, 'phoneNumber' => TRUE, 'age' => FALSE);
$submittedFields = array( 'name' => 'aspirinemaga', 'age' => 38, 'phoneNumber' => '');
$requiredFields = array_keys(array_filter($rules));
$validFields = array_keys(array_filter($submittedFields));
$missingFields = array_diff($requiredFields, $validFields);
Given
$rules = array('name' => TRUE, 'phoneNumber' => TRUE, 'age' => FALSE);
$submittedFields = array( 'name' => 'aspirinemaga', 'age' => 38, 'phoneNumber' => '');
PhoneNumber is wrong here.
$requiredFields = array_keys(array_filter($rules));
This gives you the keys of all rule elements that are TRUE.
$validFields = array_keys(array_filter($submittedFields));
Same here, your definition of what's ok is the same as php truth table for boolean conversion. If you have a more advanced check, you could pass a function name into array_filter (see below).
$missingFields = array_diff($requiredFields, $validFields);
This will get you all the fieldNames that exist in $requiredFields but are not in $validFields.
More advanced validation
$rules = array('name' => 'MORE_THAN_3', 'phoneNumber' => TRUE, 'age' => 'POSITIVE');
$submittedFields = array( 'name' => 'aspirinemaga', 'age' => 38, 'phoneNumber' => '');
$requiredFields = array_keys(array_filter($rules));
function validateField($key, $value){
// get the rule (assuming no submittedFields that have no rule)
$rule = $rules[$key];
switch($rule){
case 'MORE_THAN_3': return strlen($value) > 3; break;
case 'POSITIVE': return $value > 0; break;
}
// in case of TRUE/FALSE
return TRUE;
}
$validFields = array_keys(array_filter("validateField", $submittedFields, ARRAY_FILTER_USE_BOTH));
$missingFields = array_diff($requiredFields, $validFields);
If you wanted to do a more advanced validation, you can integrate that nicely into above solution.
Say you wanted name to be more than 3 characters and age to be positive. Write it into your rules:
$rules = array('name' => 'MORE_THAN_3', 'phoneNumber' => TRUE, 'age' => 'POSITIVE');
$submittedFields = array( 'name' => 'aspirinemaga', 'age' => 38, 'phoneNumber' => '');
Required Fields are still the same (to check if one is missing).
$requiredFields = array_keys(array_filter($rules));
Now your validate function would be something like:
function validateField($key, $value){
// get the rule (assuming no submittedFields that have no rule)
$rule = $rules[$key];
switch($rule){
case 'MORE_THAN_3': return strlen($value) > 3; break;
case 'POSITIVE': return $value > 0; break;
}
// in case of TRUE/FALSE
return TRUE;
}
Pass that into array_filter and add to ARRAY_FILTER_USE_BOTH Flag:
$validFields = array_keys(array_filter("validateField", $submittedFields, ARRAY_FILTER_USE_BOTH));
And your missing Fields stays the same.
$missingFields = array_diff($requiredFields, $validFields);
This will only work in PHP 5.6+ (because ARRAY_FILTER_USE_BOTH). Not tested, should work.