Print only matched values from two Associative arrays - php

Question

I have these two associative arrays.
I want to print the matched category_id with CHECKED and the rest Un-CHECKED
Here is what I tried.
foreach ($all_available_categories as $category) {
if(in_array($category['category_id'], $current_item_categories)){
echo 'CHECKED';
}
echo '<input type="checkbox" name="item_categories_checkbox[]" value="' .$category['category_id'] . '">' . $category['category_name'] . "</br>";
}

Answer 1

You should do sometjhing like this:
Step1: Modify your $current_item_categories array like this:
$currentCategories = array();
foreach($current_item_categories as $currCat) {
array_push($currentCategories, $currCat['category_id']);
}
Step2: Now I am using the same logic as applied by you, with a very little modification.
foreach ($all_available_categories as $category) {
if(in_array($category['category_id'], $currentCategories)){
$checked = 'checked="checked"';
}else {
$checked = "";
}
echo '<input ' . $checked . 'type="checkbox" name="item_categories_checkbox[]" value="' .$category['category_id'] . '">' . $category['category_name'] . "</br>";
}
Note: code not tested.

Answer 2

Well, you could first make an associative array of current item categories, you just key it by the category id for fast lookup.
<?php
$currentCatIds = array();
foreach ($current_item_categories as $category) {
$currentCatIds[$category['category_id']] = 1;
}
foreach ($all_available_categories as $category) {
$catid = $category['category_id'];
// Forgot this one
$checked = isset($currentCatIds[$catId]) ? 'checked' : '';
echo '<input ' . $checked . ' type="checkbox" name="item_categories_checkbox[]" value="' . $catid . '" />' . $category['category_name'] . '<br />';
}

Answer 3

foreach ($all_available_categories as $category) {
foreach ($next_available_categories as $category1) {
if($category['category_id'] == $category1['category_id']){
echo 'CHECKED'; break;
}
}
echo '<input type="checkbox" name="item_categories_checkbox[]" value="' .$category['category_id'] . '">' . $category['category_name'] . "</br>";
}

Answer 4

The idea is really quite easy: loop all categories and then for each category check whether this category is checked. You are trying to do the latter using the PHP function in_array(), but that function doesn't search multi-dimensional. So that would only work if you would have an array of category id's: $ids = array('9', '13');, and then check the category id using in_array().
So if we make these modifications it works:
$ids = array();
foreach($current_item_categories as $category) {
$ids[] = $category['category_id'];
}
foreach ($all_available_categories as $category) {
if(in_array($category['category_id'], $ids)){
echo 'CHECKED';
}
echo '<input type="checkbox" name="item_categories_checkbox[]" value="' . $category['category_id'] . '">' . $category['category_name'] . '</br>';
}
An other way to do this would of course be to use two nested loops. This would no longer require an array of id's and allows for other checks to be made:
foreach ($all_available_categories as $category) {
foreach ($current_item_categories as $c) {
if ($category['category_id'] == $c['category_id']) {
echo 'CHECKED';
}
}
echo '<input type="checkbox" name="item_categories_checkbox[]" value="' . $category['category_id'] . '">' . $category['category_name'] . '</br>';
}
Finally, you should realize that your code doesn't check the checkboxes, it only prints the word "CHECKED". If that isn't what you want, you should add a checked attribute to your input element.

Answer 5

Credit to Frog's answer.
Here is the fully working code.
$current_ids = array();
foreach ($current_item_categories as $category) {
$current_ids[] = $category['category_id'];
}
foreach ($all_available_categories as $category) {
echo '<input type="checkbox" name="item_categories_checkbox[]" value="' . $category['category_id'] . '"';
if (in_array($category['category_id'], $current_ids)) {
echo ' CHECKED ';
}
echo ' >' . $category['category_name'] . '</br>';
}