$var eq $array["something"] 1

[naq2]

Is there any way of testing if a varible is one of the values contained in an array.
All this in one line!

We can do it using a foreach loop, but I was wondering if there was a standart function for this.

Thanks.

 

[tviman]

$myarray = ("a","b","c");
$mytest = "a";
if ($mytest eq $myarray[0]){
.
.
.
do something
.
.
.
}

There's always a better way. The fun is trying to find it!

 

[naq2]

Nice! but this only thest for it on the first element!

I'm writing the function, I'll post it in 2mins.

 

[naq2]

Here it is:

sub testArrayForValue {
	my ($rArray, $value) = @_ ;
	
	foreach my $tmpValue (@$rArray) {
		if ($value eq $tmpValue) {
			return 1 ;	
		}
	}
	
	return 0 ;
}

Hope it helps.

 

[tviman]

Your code will step thru each array element ($tmpValue) and compare it to $value. I thought that's what you wanted. Did I miss something?

There's always a better way. The fun is trying to find it!

 

[naq2]

Yes... this was what I wanted to do but...

All this in one line!

I was asking if it was possible do to it WITHOUT a for loop.

 

[tviman]

Yep, missed that completely! In a word, NO! Can't be done, unless you know the exact number of array elements. But then, it wouldn't be any faster than a for loop and would probably take more overhead. The loop you have is the most efficient method available to you at this point.

There's always a better way. The fun is trying to find it!

 

[mikevh]

What about grep?

my @myarray = qw(a b c);
my $mytest = "z";
print grep(/^$mytest$/, @myarray)? "yes": "no", "\n";

 

[naq2]

euh... I think this is smart... but could you explain it a bit more?

Thanks.

 

[PaulTEG]

join

$list=join "", @array;
if (index $list, $searchstring != -1) {
 # it's in the list, ## but where
} else {
 # it's not in the list
}

it should be possible to

$list=join "", @array;
if (index (join "",@array), $searchstring != -1) {
 # it's in the list, ## but where
} else {
 # it's not in the list
}

but I haven't tried it

HTH
--Paul

It's important in life to always strike a happy medium, so if you see someone with a crystal ball, and a smile on their face ...

 

[mikevh]

print grep(/^$mytest$/, @myarray)? "yes": "no", "\n";

is a shorthand way of saying

if (grep(/^$mytest$/, @myarray)) {
    print "yes\n";
} else {
    print "no\n";
}

The original post asked for something in one line.
Here's the documentation on "?:" from perlop

Conditional Operator
Ternary "?:" is the conditional operator, just as in C. It works much
like an if-then-else. If the argument before the ? is true, the argument
before the : is returned, otherwise the argument after the : is
returned. For example:

printf "I have %d dog%s.\n", $n,
($n == 1) ? '' : "s";

Scalar or list context propagates downward into the 2nd or 3rd argument,
whichever is selected.

$a = $ok ? $b : $c; # get a scalar
@a = $ok ? @b : @c; # get an array
$a = $ok ? @b : @c; # oops, that's just a count!

The operator may be assigned to if both the 2nd and 3rd arguments are
legal lvalues (meaning that you can assign to them):

($a_or_b ? $a : $b) = $c;

Because this operator produces an assignable result, using assignments
without parentheses will get you in trouble. For example, this:

$a % 2 ? $a += 10 : $a += 2

Really means this:

(($a % 2) ? ($a += 10) : $a) += 2

Rather than this:

($a % 2) ? ($a += 10) : ($a += 2)

That should probably be written more simply as:

$a += ($a % 2) ? 10 : 2;

So, if grep returns a true value (element is found in list), print "yes", otherwise print "no".

 

[naq2]

actually I know verry well the ?: syntax... but I don't know grep.

 

[flumpy]

grep is a function that uses regexp to search variables:

http://www.perldoc.com/perl5.8.4/pod/func/grep.html

It is similar to the unix command grep, although a little more powerful.

You're in real Perlmonk territory once you've learned how to grep stuff

Matt

 

[PaulTEG]

Matt? that you??

It's important in life to always strike a happy medium, so if you see someone with a crystal ball, and a smile on their face ...

 

[flumpy]

depends.. which paul is this?

Matt Corby-Eaglen... matt[dot]corby[at]btinternet.com

 

[PaulTEG]

Nah, never heard of you


--Paul