How can I remove all newlines from hash values?

Question

I tried removing all newlines ( \\n ) from the values of a hash:

my %var_h = (  "ID"   => " This is Test 
                           This is new line TEST 


                           newline Test end ");

How can I remove all the new lines from the values of %var_h ?

I tried s/\\\\n//g but I could not get it to work.

Answer 1

s:\n::g for values %var_h;

应该可以。

Answer 2

What are you running the substitution against? You seem to want to fix only the values, so I would use the values keyword:

for my $value (values %var_h) {
  $value =~ s/\n//g;
}

An alternative (at OP's request) would be to use map and a slice though I find it a lot less clear:

@var_h{keys %var_h} = map { s/\n//g } values %var_h;

Answer 3

All other solutions remove \\n from all values of hash.

I'm not sure if this is required.

So to remove only from this one value you have:

$var_h{'ID'} =~ s/\r?\n//g;

Technically s/\\n//g should be sufficient, but I have the habit of adding \\r? before it, so it will handle Windows-styled new lines as well.