PHP Array function array_key_exists () Find out if the array key name exists

Contents of this section: PHP array function array_key_exists () Array_key_exists () defines and uses the array_key_exists () function to determine whether a specified key exists in an array, returns TRUE if the key exists, or false otherwise. The syntax array_key_exists (key,array) parameter describes key required. Specifies the key name. Array required. Specifies the input array. Example 1,php the array_key_exists () of an array function. $a =array ("a" and "Dog", "b" = "Cat"); if (Array_key_exists ("a", $a)) { echo "Key exists!"; } Else { echo "Key does not exist!"; } ?> Copy Code Output: Key exists! Example 2,php the array_key_exists () of an array function. $a =array ("a" and "Dog", "b" = "Cat"); if (Array_key_exists ("C", $a)) { echo "Key exists!"; } Else { echo "Key does not exist!"; } ?> Copy Code Output: Key does not exist! Example 3,php the array_key_exists () of an array function. $a =array ("Dog", Cat "); if (array_key_exists (0, $a)) { echo "Key exists!"; } Else { echo "Key does not exist!"; } ?> Copy Code Output: Key exists!

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