Finding the minimum value's key in an associative array

问题

In PHP, say that you have an associative array like this:

$pets = array(
    "cats" => 1,
    "dogs" => 2,
    "fish" => 3
);

How would I find the key with the lowest value? Here, I'd be looking for cats.

Is there some built in PHP function that I've missed which does this? It would also be great if there was a solution that accounted for several values being identical, as below:

$pets = array(
    "cats" => 1,
    "dogs" => 1,
    "fish" => 2
);

Above, I wouldn't mind if it just output either; cats or dogs.

Thanks in advance.

回答1:

array_keys is your friend:

$pets = array(
    "cats" => 1,
    "dogs" => 2,
    "fish" => 3
);
array_keys($pets, min($pets));  # array('cats')

P.S.: there is a dup here somewhere on SO (it had max instead of min, but I can distinctly remember it).

回答2:

Thats how i did it.

$pets = array(
    "cats" => 1,
    "dogs" => 2,
    "fish" => 3
);

array_search(min($pets), $pets);

I hope that helps

回答3:

Might try looking into these:

natcasesort(array)
natsort(array)

回答4:

$min_val = null;
$min_key = null;
foreach($pets as $pet => $val) {
  if ($val < $min_val) {
    $min_val = $min;
    $min_key = $key;
  }
}

You can also flip the array and sort it by key:

$flipped = array_flip($pets);
ksort($flipped);

Then the first key is the minimum, and its value is the key in the original array.

回答5:

find the highest value

print max(120, 7, 8, 50);

returns --> 120

$array = array(100, 7, 8, 50, 155, 78);
print max($array);

returns --> 155

find the lowest value

print min(120, 7, 8, 50);

returns --> 7

$array = array(50, 7, 8, 101, 5, 78);
print min($array);

returns --> 5

来源：https://stackoverflow.com/questions/1588353/finding-the-minimum-values-key-in-an-associative-array

标签

php

associative-array