Array @p is a multiline array, e.g. $p[1] is the second line.
This code will explain what I want:
$size=@p; # line number of array @p
for($i=0; $i<$size; $i++)
{
@p{$i}= split(/ +/,$p[$i]);
}
I want the result should be like this:
@p0 = $p[0] first line of array @p goes to array @p0;
@p1 = $p[1] second line of array @p goes to array @p1;
...
...
and so on.
But above code does not work, how can I do it?
It is a bad idea to dynamically generate variable names.
I suggest the best solution here is to convert each line in your @p array to an array of fields.
Lets suppose you have a better name for @p, say @lines. Then you can write
my @lines = map [ split ], <$fh>;
to read in all the lines from the file handle $fh and split them on whitespace. The first field of the first line is then $lines[0][0]. The third field of the first line is $lines[0][2] etc.
First, the syntax @p{$i} accesses the entry with the key $i in a hash %p, and returns it in list context. I don't think you meant that. use strict; use warnings; to get warned about undeclared variables.
You can declare variables with my, e.g. my @p; or my $size = @p;
Creating variable names on the fly is possible, but a bad practice. The good thing is that we don't need to: Perl has references. A reference to an array allows us to nest arrays, e.g.
my @AoA = (
[1, 2, 3],
["a", "b"],
);
say $AoA[0][1]; # 2
say $AoA[1][0]; # a
We can create an array reference by using brackets, e.g. [ @array ], or via the reference operator \:
my @inner_array = (1 .. 3);
my @other_inner = ("a", "b");
my @AoA = (\@inner_array, \@other_array);
But careful: the array references still point to the same array as the original names, thus
push @other_inner, "c";
also updates the entry in @AoA:
say $AoA[1][2]; # c
Translated to your problem this means that you want:
my @pn;
for (@p) {
push @pn, [ split /[ ]+/ ];
}
There are many other ways to express this, e.g.
my @pn = map [ split /[ ]+/ ], @p;
or
my @pn;
for my $i ( 0 .. $#p ) {
$pn[$i] = [ split /[ ]+/, $p[$i] ];
}
To learn more about references, read
split /[ ]+/ actually wants split ' '