The difference between array_key_exists and isset in php

This article introduces the difference between array_key_exists and isset in the PHP language. Friends in need can refer to it.

What are the differences between array_key_exists and isset in php?

1. The judgment of array values ​​is different. If the value is null or '' or false, isset returns false and array_key_exists returns true; 2. The execution efficiency is different. isset is a built-in operator, array_key_exists is a PHP built-in function, and isset is faster. 3. When using isset to access a non-existent index array value, an E_NOTICE php error message will not be caused; 4. array_key_exists will call get_defined_vars to determine whether the array variable exists, and isset is not used;