如何检查数组中是否存在给定的键或索引？

Question

I have created an array of data from mysql database. This is how that array looks like:

// Fetch all the records:
while ($stmt->fetch()) {

    $output  =  "<a>
";
    $output .=      "<h3>{$product_name}</h3>
";
    $output .=      "<span class='price'><span class='amount'>BD.{$price}</span></span>
";
    $output .=  "</a>
";
    $output .=  "<div class='short_desc'>
";
    $output .=          "$product_des
";       
    $output .=  "</div>
";

    //Add output to array
    $products[] = $output;      
}

Since I want to use this array values from outside my while loop and This is how I use this $products[] array in my page.

echo $products[0];
echo $products[1];
echo $products[2];
echo $products[3];

My question is if this $products[] array have one result set I can get an error.

My error message is like this: An error occurred in script 'C:\wamp\www\Computer\index.php' on line 208: Undefined offset: 2

So I tried to fix this problem using array_key_exists() function like this way for each echo:

if(!empty($products) && array_key_exists("$products[1]", $products)) echo $products[1]; else echo "No Product";

But still I can get error. Can anybody tell me what is wrong with this?

Thank you.

Answer 1

You probably want something like:

if( ! empty($products) ) {
    $ids = array(0, 1, 2, 3, 4, 5);
    foreach ( $ids as $id ) { 
      if ( ! empty($products[$id]) ) echo $products[$id];
    }
} else { 
   echo "No Product";
}