正确使用PHP设置[关闭]

I would noramlly try to use the isset operator as below, where $x has to be forcefully set to null or $y if present

$x = isset($y) ? $y : null;

However below code does something similar. But, I am forced to write 'dummy' code in the below solution. How can I prevent this?

isset($y) ? $x = $y: 'dummy';

Which solution #1 or #2 would be preferred?

The principle which says that the "code is for programmers to read - and the binary is for the machine to read" applies here.

$x = isset($y) ? $y : null; is clean and straightforward

while

isset($y) ? $x = $y: 'dummy'; is convoluted and oblique.