PHP - 在数组中查找唯一值

Question

I am creating an ecommerce site and am trying to get a list of top selling products.

The following example shows an array of product ids from sales, and is outputting the top selling products in the form of 'product id' x 'number of sales'

<?php
$product_ids = [58,58,68,39,4,118,14,54,39,118,58];
$top_selling_products = "";

$product_sales = array_count_values($product_ids);
arsort($product_sales);
$i = 0;
foreach($product_sales as $sales){
    $i++;
    $product_id = array_search($sales,$product_sales);
    $top_selling_products .= $product_id.' x '.$sales.'<br />';
    if($i == 5){break;}
}

echo $top_selling_products;
?>

However, it's not exactly doing what I want, at present this is outputting the following:

58 x 3
118 x 2
118 x 2
54 x 1
54 x 1

Where it should be:

58 x 3
118 x 2
39 x 2
54 x 1
14 x 1

It is getting the last item in the array with the same index so when there are two or more products with the same amount of sales it is not picking them up.

What would be the best way to get all unique ids?

Answer 1

You already have what you need in $product_sales :

foreach($product_sales as $id => $count){
    $i++;
    $top_selling_products .= $id.' x '.$count.'<br />';
    if($i == 5){break;}
}

Answer 2

Your code can be simplified to use something like array_map() :

arsort($product_sales);
$output = array_map(function($sales, $pid) {
    return $pid.' x '.$sales;
}, $product_sales, array_keys($product_sales));
echo implode('<br />', $output);

Answer 3

<?php

$product_ids      = [58,58,68,39,4,118,14,54,39,118,58];
$product_sales    = array_count_values($product_ids);
arsort($product_sales);
$top_five_sellers = array_slice($product_sales, 0, 5, true);
foreach($top_five_sellers as $id => $count)
    echo $id.' x '.$count."\n";

Output:

58 x 3
39 x 2
118 x 2
68 x 1
4 x 1

Answer 4

You can achieve your goal by using array_count_values + Simple foreach + Sort array by Keeping key with arsort

$product_ids = [58,58,68,39,4,118,14,54,39,118,58];
$arr = array_slice(array_count_values($product_ids), 0, 5, true);
arsort($arr);
$str = "";
foreach($arr as $k=>$v)
  $str .= "$k X $v \n";
echo $str;

Live Demo

Output is as :

58 X 3 
118 X 2 
39 X 2 
68 X 1 
4 X 1