Question

我有这个关联数组，我想从这些数组中得到price的最低值

array (size=3)
  0 => 
    array (size=21)
      'quantity' => int 6
      'product_id' => int 3
      'category_id' => string '2' (length=1)
      'price' => float 18.73
  1 =>
    array (size=21)
      'quantity' => int 21
      'product_id' => int 6
      'category_id' => string '1' (length=1)
      'price' => float 0.26
  2=>
    array (size=21)
      'quantity' => int 34
      'product_id' => int 6
      'category_id' => string '1' (length=1)
      'price' => float 0.63

我试过了

foreach ($products as $key_id => $prod) {
    $lowest = $prod['price'];
    if($prod['price'] < $lowest) {
        // what to do here
    }
}

我想获得价格最低的产品及其product_id，例如

product_id => 6 , price => 0.26

Answer 1

在php＆gt; = 5.5

$min = min(array_column($products, 'price'));

在php＆gt; = 5.3（由deceze建议）

$min = min(array_map(function (array $product) { return $product['price']; }, $products));

在php＆gt; = 5.0

中

$prices = array();

foreach ($products as $product) {
  $prices[] = $product['price'];
}

$min = min($prices);

修改

要查找product_id，您可以使用：

$min = PHP_INT_MAX; $product_id = 0; foreach ($products as $product) { if ($product['price'] < $min) { $product_id = $product['product_id']; $min = $product['price']; } }

array column manual page
min manual page
array_map manual page
anonymous functions manual page

Answer 2

这是减少操作非常合适的地方：

$lowest = array_reduce($products, function ($lowest, array $product) {
    return !$lowest || $product['price'] < $lowest ? $product['price'] : $lowest;
});

Answer 3

如果价格低于当前最低价格，则只应设置最低价格。

// Set $low to the max value
$low = PHP_INT_MAX;
foreach ($products as $key_id => $prod) {
    // If the price is lower than the current lowest, change the lowest price
    if($prod['price'] < $lowest) {
        $low = $prod['price'];
    }
}

两级String的最低值索引关联数组

3 个答案: