粘性选择php。 其他堆栈溢出答案对我不起作用

Question

So I tried going with the answer from Sticky Select Option which ended up looking like this

<option value="2" <?php if(isset($yourDilution && $yourDilution == 2)){ echo 'selected = "selected" '; }?>>1:1</option>

and that breaks my code and gives me a syntax error. Alternatively I have

<option value="3" <?php if($yourDilution == 3) echo 'selected="selected"'; ?>>1:2</option>

and that gives me the problem I had before coming here to look at other answers on the topic. The problem is that the drop down gets filled with Notice: Undefined variable $yourDilution etc. Thanks for taking a minute to point me in the right direction.

Answer 1

if(isset($yourDilution && $yourDilution == 2))

应该

if(isset($yourDilution) && $yourDilution == 2)