How do I print a partial array?

shampoo7 has asked for the wisdom of the Perl Monks concerning the following question: ⭐ (arrays)

I am trying to print an array. But not all the elements are intialize. i.e.

@b[0]=c; 
@b[1]=undef;
@b[3]=undef;
@b[4]=a;
[download]

so when i use print "@b", I want only @b[0] and @b[4] to be printed. How do I skip the undef elements?

Edited 2001/06/13 by Ovid

Originally posted as a Categorized Question.

Comment on How do I print a partial array? Download Code

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Re: How do I print a partial array?⭐ by MeowChow (Vicar) on Jun 13, 2001 at 22:21 UTC
grep anyone? `print grep defined $_, @b;` [download]	[reply] [d/l]
Re: How do I print a partial array? by Albannach (Monsignor) on Jun 13, 2001 at 21:49 UTC
You can test whether an element has been defined with the sensibly named defined function, so one way might be something like: `for my $element (@a) { print $element if defined($element); }` [download]	[reply] [d/l]
Re: How do I print a partial array? by Sifmole (Chaplain) on Jun 13, 2001 at 22:15 UTC
`print map { defined $_ ? $_ : ''; } @b;` would be one way.	[reply] [d/l]
Re: How do I print a partial array? by dragonchild (Archbishop) on Jun 13, 2001 at 21:54 UTC
If you already know what elements you want to print, then doing something like `print @b[0,4,6..8], "\n";` will print just those elements. This is called an array slice.	[reply] [d/l]
Re: How do I print a partial array? by Bloodelf (Beadle) on Jun 19, 2001 at 01:08 UTC
Another way.... `foreach ( @b ) { print "$_\n" if defined $_; }` [download] Edited by davido: Added "defined" to conditional so that elements containing '0' would still print, while undefined elements are skipped.	[reply] [d/l]


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