array_unique with two arrays

Question

I have two arrays of the same length ($search_type, $search_term). I want to remove any duplicates in the sense of there being searches that have the same type and search term (ie $search_type[$a] == $search_type[$b] && $search_term[$a] == $search_term[$b]).

I'm aware that I could write this using loops, was wondering if there's a simpler (but equally efficient) way that takes advantage of built in functions?

Answer 1

Try either array_intersect() which will take two arrays and return an array where a value in array A exists in array B. Or array_diff() which does the opposite and returns an array of all values in A that don't exist in B.

Answer 2

Ok, here's an overly complex ad-hoc function foo() (lacking error handling, documentation and testing) that combines those two arrays. array_unique() takes care of the duplicates.

<?php
$search_term = array('termA', 'termB', 'foo'=>'termC', 'bar'=>'termD', 'termB', 'termA');
$search_type= array('typeA', 'typeB', 'foo'=>'typeC', 'bar'=>'typeD', 'typeB', 'typeA');

$x = foo(array('term', $search_term), array('type', $search_type));
$x = array_unique($x, SORT_REGULAR);
var_dump($x);

function foo() {
  $rv = array();
  $params = func_get_args();
  foreach ( array_keys($params[0][1]) as $key ) {
    $rv[$key] = array();  
    foreach( $params as $p ) {
      $rv[$key][$p[0]] = $p[1][$key];  
    }
  }
  return $rv;
}

prints

array(4) {
  [0]=>
  array(2) {
    ["term"]=>
    string(5) "termA"
    ["type"]=>
    string(5) "typeA"
  }
  [1]=>
  array(2) {
    ["term"]=>
    string(5) "termB"
    ["type"]=>
    string(5) "typeB"
  }
  ["foo"]=>
  array(2) {
    ["term"]=>
    string(5) "termC"
    ["type"]=>
    string(5) "typeC"
  }
  ["bar"]=>
  array(2) {
    ["term"]=>
    string(5) "termD"
    ["type"]=>
    string(5) "typeD"
  }
}

Answer 3

It doesn't look like there's a simple way to solve the problem using just built-in functions.

This (at least logically) should work.

$search_terms = array('a', 'b', 'c', 'c', 'd', 'd');
$search_types = array( 1,   2,   3,   4,   5,   5);

$terms = array_fill_keys($search_terms, array());
// Loop through them once and make an array of types for each term
foreach ($search_terms as $i => $term)
    $terms[$term][] = $search_types[$i];

// Now we have $terms = array('a' => array(1),
//                            'b' => array(2),
//                            'c' => array(3, 4),
//                            'd' => array(5, 5)
//                      );

// Now run through the array again and get rid of duplicates.
foreach ($terms as $i => $types)
    $terms[$i] = array_unique($types);

Edit: Here's a shorter and presumably more efficient one where you end up with a less pretty array:

$search_terms = array('a', 'b', 'c', 'c', 'd', 'd');
$search_types = array( 1,   2,   3,   4,   5,   5);

$terms = array_fill_keys($search_terms, array());
// Loop through them once and make an array of types for each term
foreach ($search_terms as $i => $term)
    $terms[$term][$search_types[$i]] = 1;

// Now we have $terms = array('a' => array(1 => 1),
//                            'b' => array(2 => 1),
//                            'c' => array(3 => 1, 4 => 1),
//                            'd' => array(5 => 1)
//                      );