Checking array key for existence

Question

I want to check the key for existence in the $ arr array using the ternary operator. And if true , then display this key.

<?php $arr = array("test" => 1, "some" => 2); echo "test" ? array_key_exists("test", $arr) : echo "такого ключа нет"; ?>

But it gives an error when writing. But where is the mistake?

usually write echo array_key_exists("test", $arr) ? 'ключ есть' : 'ключа нет';
echo array_key_exists("test", $arr) ? 'ключ есть' : 'ключа нет';
and how to make the 'key have' instead of the name of this key?
you can’t do it in any way, you take it somewhere before checking it, so you can insert a 'key in' inside

Accepted Answer · 2016-12-16T08:51:28

Incorrectly root construction. Logically, it should look like this:

 echo (что-то);

The brackets are optional, but it will be clearer for you. Now insert the ternary operator array_key_exists("test", $arr) ? 'ключ есть' : 'ключа нет' inside the parentheses array_key_exists("test", $arr) ? 'ключ есть' : 'ключа нет' array_key_exists("test", $arr) ? 'ключ есть' : 'ключа нет' which literally means true ? действие_для_true : действие_иначе; true ? действие_для_true : действие_иначе;

It turns out, we remove the brackets at the same time:

 echo array_key_exists("test", $arr) ? 'ключ есть' : 'ключа нет';

Working Example: http://ideone.com/H68pwa

With the output of the key from the variable total:

 $arr = array("test" => 1, "some" => 2); $key = 'test'; echo array_key_exists($key, $arr) ? "ключ $key есть" : 'ключа нет';

and how to make the 'key have' instead of the name of this key?

Checking array key for existence

1 answer 1

More articles: