PHP: get array value as in Python?

Question

In Python I can use "get" method to get value from an dictionary without error.

a = {1: "a", 2: "b"}
a[3] # error
a.get(3, "") # I got empty string.

So I search for a common/base function that do this:

function GetItem($Arr, $Key, $Default){
    $res = '';
    if (array_key_exists($Key, $Arr)) {
        $res = $Arr[$Key];
    } else {
        $res = $Default;
    }
    return $res;
}

Have same function basicly in PHP as in Python?

Thanks: dd

Answer 1

isset() is typically faster than array_key_exists(). The parameter $default is initialized to an empty string if omitted.

function getItem($array, $key, $default = "") {
  return isset($array[$key]) ? $array[$key] : $default;
}

// Call as
$array = array("abc" => 123, "def" => 455);
echo getItem($array, "xyz", "not here");
// "not here"

However, if an array key exists but has a NULL value, isset() won't behave the way you expect, as it will treat the NULL as though it doesn't exist and return $default. If you expect NULLs in the array, you must use array_key_exists() instead.

function getItem($array, $key, $default = "") {
  return array_key_exists($key, $array) ? $array[$key] : $default;
}

Answer 2

Not quite. This should behave the same.

function GetItem($Arr, $Key, $Default = ''){
    if (array_key_exists($Key, $Arr)) {
        $res = $Arr[$Key];
    } else {
        $res = $Default;
    }
    return $res;
}

The first line in your function is useless, as every code path results in $res being overwritten. The trick is to make the $Default parameter optional as above.

Keep in mind that using array_key_exists() can cause significant slowdowns, especially on large arrays. An alternative:

function GetItem($Arr, $Key, $Default = '') {
  return isset($Arr[$Key]) ? $Arr[$Key] : $Default;
}

Answer 3

There is no base function to do that in my mind.

Your GetItem is a good way to do what you wanna do :)

Answer 4

Yes. or

function GetItem($Arr, $Key, $Default) {
  return array_key_exists($Key, $Arr)
      ? $Arr[$Key]
      : $Default;
}

Answer 5

php7 is out for a long time now so you can do

$Arr[$Key] ?? $default