PHP isset（）函数返回false [关闭]

Please look at my code...

$sample = 'done';

$sample1 = 'welcome';

echo isset($sample) ? $sample : isset($sample1) ? $sample1 : '';

this will returns as welcome. But how variable $sample is present in this sense result would be done .. kindly help me?

$sample = 'done';

$sample1 = 'welcome';

echo isset($sample) ? $sample : isset($sample) ? $sample : '';

You're missing a $ in front of sample1 =

I suspect this is a problem with the order of operations in your last line. This is, in a word, confusing:

isset($sample) ? $sample : isset($sample1) ? $sample1 : '';

If you want separate conditional clauses, explicitly separate them with parentheses:

isset($sample) ? $sample : (isset($sample1) ? $sample1 : '');

Otherwise I suspect everything before the second conditional statement is collectively evaluating to true and thus outputting $sample1.