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Re^3: Conditional Operator Confusion

by Herkum (Parson)
on Nov 30, 2006 at 16:44 UTC ( [id://586999]=note: print w/replies, xml ) Need Help??


in reply to Re^2: Conditional Operator Confusion
in thread Conditional Operator Confusion

The trinary is much like any other operator, for example ==. Lets try this example,

my $result = $a == $b

Here, you get the result of the == operator, is $a equal $b. If they match it returns true, if they don't match it returns false.

The trinary works in a similar manner except you are setting the value returned instead of the implied value of other operators.

my $result = $a == $b ? 1 : 0;

This does the same thing as the first example, except you are explicitly setting the value returned. Does this help?

Replies are listed 'Best First'.
Re^4: Conditional Operator Confusion
by Melly (Chaplain) on Nov 30, 2006 at 17:03 UTC

    Not really... I'm sure I'm being really dumb here, but I still don't understand, in the following example, why $x gets set to "FALSE"... just very, very confused...

    1==1?$x='TRUE':$y='FALSE'; print "x=$x\n";
    Tom Melly, pm@tomandlu.co.uk

      The conditional operator has higher precedence than the assignment operator, so
      $c?$x='TRUE':$y='FALSE'
      is the same as
      ($c?$x='TRUE':$y)='FALSE'

      The addition operator has higher precedence than the conditional operator, so
      $c?$x+2:$y+3
      is the same as
      $c?$x+2:($y+3)

      If you want to do assignments, use if or add parens. Think of as the conditional operator as an operator that returns something.

        Thanks - I think I've finally got it (with some help from the chatterbox as well).

        All of which goes to confirm something a coworker once told me..

        Me: What's the precedence in <lang> for these operators?
        CW: Who cares? Use brackets - it's easier to read and
            you won't get screwed...
        
        Tom Melly, pm@tomandlu.co.uk

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