Question 263557 in PHP Question posted in
Official manual can be found here.

Php – Undefined array key[ Will it be a problem?

I want to ask a if undefined array key can cause problems later on.

I have a product list in php file where when i choose different options like colour and size, it shows different prices and images accordingly. Everything works fine but in the apache error log it mentions an array key is undefined.

Will this cause problems?

Tags:

2

Answers


  1. 0

    Of course, an error is always bad. You should try to figure out, what the error is and which key is causing the error.
    It can crash your application, create undefined behavior or other side effects.

    If the key is essential, it must be present. Otherwise, you could test the array, before accessing the array:

    $arr = ['foo' => 42];
if (isset($arr['bar']) {
    echo $arr['bar'];
} else {
    // do some error handling
}
    Login or Signup to reply.
  2. 0

    In PHP, you can use arrays to store and retrieve values. Here’s a basic example of creating an array and fetching values from it:

    // Create an indexed array
$fruits = array("apple", "banana", "cherry", "date");

// Access elements by index (0-based)
$firstFruit = $fruits[0]; // Retrieves "apple"
$secondFruit = $fruits[1]; // Retrieves "banana"
$thirdFruit = $fruits[2]; // Retrieves "cherry"
$fourthFruit = $fruits[3]; // Retrieves "date"

// Output the retrieved values
echo "First fruit: " . $firstFruit . "<br>";
echo "Second fruit: " . $secondFruit . "<br>";
echo "Third fruit: " . $thirdFruit . "<br>";
echo "Fourth fruit: " . $fourthFruit . "<br>";

    In PHP, you can use a foreach loop to iterate over the elements of an array. Here’s a basic example of how to use a foreach loop with an indexed array:

    $fruits = array("apple", "banana", "cherry", "date");

// Iterate over the elements in the array
foreach ($fruits as $fruit) {
    echo "Fruit: " . $fruit . "<br>";
}
    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search