PHP: How do I compare values in nested associative arrays? - php

Question

I'm trying to wrap my head around how to accomplish this…
I have an that's something like:
$contributors = array(
[0] => array(
[name] => 'John',
[role] => 'author',
),
[1] => array(
[name] => 'Gail',
[role] => 'author',
),
[2] => array(
[name] => 'Beth',
[role] => 'illustrator',
),
)
I'm trying to use this information to construct a detailed byline, like:
Written by John and Gail. Designed by Beth.
I need to compare each role to the previous and next ones in order to:
Use a label before the first instance of each role
Separate multiple instances of the same role with a comma
Use "and" instead of a comma before the last instance of each role
I'm no PHP expert so I'm having a hard time figuring out how to approach this! I have a function to output the right label depending on the role, but it's the comparisons I can't seem to figure out. I've considered foreach and while loops, but neither seems up to the job. I've never used a for loop so I don't know if it applies.
Some additional background:
I'm working with WordPress and the Advanced Custom Fields plugin.
$contributors is the value of an ACF Repeater field, where name and role are subfields. (I've simplified the names to make things easier.)

Answer 1

You can group the array per role and use array_pop to remove the element. implode the remaining array elements and just append the popped value.
$contributors = array(
array(
"name" => 'John',
"role" => 'author',
),
array(
"name" => 'Gail',
"role" => 'author',
),
array(
"name" => 'Jose',
"role" => 'author',
),
array(
"name" => 'Thomas',
"role" => 'author',
),
array(
"name" => 'Beth',
"role" => 'illustrator',
),
array(
"name" => 'Mary',
"role" => 'producer',
),
array(
"name" => 'Criss',
"role" => 'producer',
),
);
//Grouped the names according to role
$grouped = array_reduce($contributors, function($c, $v) {
if ( !isset( $c[ $v['role'] ] ) ) $c[ $v['role'] ] = array();
$c[ $v['role'] ][] = $v['name'];
return $c;
}, array());
//Construct final Array
$final = array();
foreach( $grouped as $key => $group ) {
$last = array_pop( $group );
if ( count( $group ) == 0 ) $final[ $key ] = $last; /* One one name on the role, no need to do anything*/
else $final[ $key ] = implode( ", ", $group ) . " and " . $last;
}
echo "<pre>";
print_r( $final );
echo "</pre>";
This will result to:
Array
(
[author] => John, Gail, Jose and Thomas
[illustrator] => Beth
[producer] => Mary and Criss
)
You can now use it as
echo 'Written by ' . $final["author"] . '. Designed by ' . $final["illustrator"] . '. Produced by ' . $final["producer"];
And will result to:
Written by John, Gail, Jose and Thomas. Designed by Beth. Produced by
Mary and Criss

Answer 2

You can try like this -
$contributors = array(
array(
'name' => 'John',
'role' => 'author',
),
array(
'name' => 'Gail',
'role' => 'author',
),
array(
'name' => 'Ali',
'role' => 'author',
),
array(
'name' => 'Beth',
'role' => 'illustrator',
)
);
#This function prepare array to expected String
function PrepareArray($data){
$combined = '';
if (count($data)>1) {
$last = array_slice($data, -1);
$first = join(', ', array_slice($data, 0, -1));
$both = array_filter(array_merge(array($first), $last), 'strlen');
$combined = join(' and ', $both);
}else{
$combined = implode('', $data);
}
return $combined;
}
$authors = array();
$designers = array();
foreach ($contributors as $key => $value) {
if ($value['role']=='author') {
$authors[] = $value['name']; #Keep Authors name in Array
}else if ($value['role']=='illustrator') {
$designers[] = $value['name']; #Keep Designers name in Array
}
}
$authors = PrepareArray($authors);
$designers = PrepareArray($designers);
echo "Written by {$authors}. Designed by {$designers}.";
Output :
Written by John, Gail and Ali. Designed by Beth.

Answer 3

Try below code:
<?php
$contributors = array(
0 => array(
'name' => 'John',
'role' => 'author',
),
1 => array(
'name' => 'Gail',
'role' => 'author',
),
2 => array(
'name' => 'Beth',
'role' => 'illustrator',
),
3 => array(
'name' => 'Albert',
'role' => 'author',
),
);
$labels = ['author'=>'Written by', 'illustrator'=>'Designed by', 'producer'=>'Produced by'];
$new_contributors = [];
foreach($contributors as $cont){
$new_contributors[$cont['role']][] = $cont['name'];
}
$str = '';
foreach($labels as $role=>$label){
if(isset($new_contributors[$role]) && is_array($new_contributors[$role])){
$str .= ' '.$label.' ';
foreach($new_contributors[$role] as $key=>$new_contributor){
$count = count($new_contributors[$role]);
if(($count - $key) == 1 ){
$str .= ' and ';
$str .= $new_contributor;
}else if(($count - $key) == 2){
$str .= $new_contributor;
}else{
$str .= $new_contributor.', ';
}
}
}
}
echo $str;