PHP to determine if there is a method for specifying keys (key) in an array _php tips

This article is an example of a method for specifying a key in the array of PHP judgments. Share to everyone for your reference. The specific analysis is as follows:

PHP has two functions to determine whether the array contains the specified keys, respectively, Array_key_exists and Isset

The array_key_exists syntax is as follows

Array_key_exists ($key, $array)

If the key exists to return true isset function syntax is as follows

Isset ($array [$key])

If the key exists to return true

The demo code is as follows:

<?php
$array = Array ("Zero" => "PHP", "one" => "Perl", "two" => "Java");
Print (' is ' one ' defined? '. Array_key_exists ("One", $array). " \ n ");
Print (' is ' 1 ' defined? '. Array_key_exists ("1", $array). " \ n ");
Print ("is ' two ' defined?"). Isset ($array ["two"]). " \ n ");
Print (' is ' 2 ' defined? '. Isset ($array [2]). " \ n ");
? >

The returned results are as follows:

Is ' one ' defined? 1 is
' 1′defined?
Is ' two ' defined? 1 is
' 2′defined?

I hope this article will help you with your PHP program design.