Getting single element from an array

[gurpreetsingh13]

Hi Monks,

Was just trying some statements and wondered why a similar one doesn't work.

print ("adf","ff","f"); # Gladly prints the list
print ("adf","ff","f")[1]; #Gives a syntax error
$val=("adf","ff","f")[1];print $val; #Works easily
print join "",("adf","ff","f"); #Works
print join "",("adf","ff","f")[1]; #Works since treated in list contex
+t

I might be wrong on some basics. But why the 2nd statement fails. I mean if such a thing works, then we can directly use it to print a single element returned from a function or method(like in Java).e.g.

(sort {$a<=>} @lst)[0] # an alternative way to get min value from some
+ numeric list.

Similarly in Java we can do:

obj.method()[2] #when we know that method returns an array

Tried to search a little about this, but could not find a reasonable thread for the same. Sorry again if this is some conceptual weakness of mine.

[choroba]

The ( in the second case is taken by the parser as starting the argument list. When the [ is being parsed, it is already too late to change mind. You can use + to disambiguate:

print +("adf","ff","f")[1];

[Anonymous Monk]

? What is the difference between

print( 1,2,3 );
print( ( 1,2,3 )[1] );

? How would perl know what you mean by

print( 1,2,3 )[1];

If knows the difference if you write   print +( 1,2,3 )[1];

[Anonymous Monk]

obj.method()[2] #when we know that method returns an array

But you still have to wrap it with  System.out.println( ... ); , you don't get to omit () in java, in java () on calls are mandatory, but not in perl

[gurpreetsingh13]

Got the point Sir. Thanks.

[itnomad]

This works:  print qw[adf ff f ][1];

[brx]

print ("adf","ff","f"); # Gladly prints the list
print ("adf","ff","f")[1]; #Gives a syntax error

Think to print() as a subroutine: you can write myfunc(...); but myfunc(...)[1]; is wrong.

With a "gift package ( )", perl will be happy: myfunc( (...][1] );

perl -e 'sub myfunc { return @_;}; my @res = myfunc(('a','b','c')[1]);print @res;' OK

perl -e 'sub myfunc { return @_;}; my @res = myfunc('a','b','c')[1];print @res;' WRONG