Yahoo Interview Question
Production EngineersAn example of three kinds of variables
/home/gkhurana> perl
#Scalar
print "\nPrinting scalar\n";
$a = "10";
$b = "HI how are you ";
print $a;
print "\n";
print $b;
print "\n";
#Array
print "\nPrinting array values";
@a=(1,2,3,4);
@b=("do","you","know","me");
@c=('do','you');
foreach(@a,@b,@c)
{
print "$_\n";
}
#hash
%a = ( 1 =>'one' , 2=>"two");
print "\nPrinting Hash\n";
while (($key, $value)=each %a)
{
print "keys = $key value = $value \n";
}
^D
#Output below
Printing scalar
10
HI how are you
Printing array values1
2
3
4
do
you
know
me
do
you
Printing Hash
keys = 1 value = one
keys = 2 value = two
/home/gkhurana>
Basic Variables in Perl:
1.Scalar Variables -->Scalar variables are simple variables containing only one element--a string, a number, or a reference.
2.Array Variables--> Arrays contain a list of scalar data (single elements).Denoted by @
3.Hashes -->are complex lists with both a key and a value part for each element of the list.
To see if a file exists: First open a file ..if it doesnt open display error
open MYFILE , "filename" || "die $!";
scalar variable $variableName
- durgesh October 07, 2008array variable @variableName
hash variable %variable_name
using -e option to see if a file exists
if( -e $fileName)
{
}