Per your data set as it stands just now, here is an SSCCE:

use strict;
use warnings;

use Test::More tests => 1;

my @have = (
'99~Arun~Kumar~Mobilenum:
1234-567 , from Earth
Human',
'98~Mahesh~Babu~Mobilenum:
5678-901 , from Earth
Human'
);
my @want = (
'99~Arun~Kumar~Mobilenum: 1234-567 , from Earth Human',
'98~Mahesh~Babu~Mobilenum: 5678-901 , from Earth Human'
);

for (@have) {
    s/\n/ /sg;
}

is_deeply (\@have, \@want);
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Since you haven't said what your input record separator is I have created the array by hand. See also How to ask better questions using Test::More and sample data.