Perl if statement confusion

Question

This code is an `if` statement; I want to test whether `$rtgene` contains `trn`. I tested the code with `$rtgene= nad3`: ``` if ($rtgene!~/trn/){ $end=$data[$i][0]+100; } else{ $end =$data[$i][1]; } print $end; ``` This is an alternative expression that doesn't work: ``` ($rtgene!~/trn/)? $end=$data[$i][0]+100 : $end=$data[$i][1]; print $end; ``` The problem is in the first code (normal if else statement) it works and give me the expected results, but the alternative one (last line) it's not working; it always executes the `else` statement. Question: What is the cause of this problem? How to fix it?

Accepted Answer

Since you are trying to assign one of two values to `$end` based on a condition, why not write the conditional expression like that:

```
$end = ($rtgene !~ /trn/) ? $data[$i][0]+100 : $data[$i][1];
print $end;
```

This avoids the precedence problem accurately diagnosed by ysth and is quite a bit easier to understand.

Perl can be used to write inscrutable code; it is not a good idea to make all your code inscrutable, though. Stacking the assignment and print on a single line is tending towards inscrutability.

Perl if statement confusion

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