Assign value to @_ : Special Variables « Language Basics « Perl






  1. Perl
  2. Language Basics
  3. Special Variables

Assign value to @_

   

sub addem
{
    ($value1, $value2) = @_;
    $value1 + $value2;
}

@_ = (2, 2);
$value = &addem;

print "2 + 2 = $value\n";








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4.The list separator is a comma
5.The list separator is the empty string
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7.Special Hashes: The %ENV Hash
8.The %SIG hash sets signal handlers for signals.
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10.A program that uses the $" (dollar and quotation) variable.
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13.A program that uses the $\(dollar and slash) variable.
14.A simple program that assigns to $_ using .
15.A simple version of the cat command using $_.
16.ARGV and the Null Filehandle
17.ARGV in Perl represents the command-line arguments.
18.Aliases and Values
19.Alternative names for Perl system variables.
20.Assign elements in @_ to scalar
21.Assign string array to @ARGV by using qw
22.Build the ARGV array with qw function
23.@_ has runtime scope.
24.A more expanded version for showing how to use the $_
25.Built-in variables: $_
26.Call-by-Reference and the @_ Array
27.Capturing fatal errors
28.Catching the sigINT signal
29.Code the $_ specifically
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31.Error message is stored in $!
32.Extracts information from the $] variable.
33.$! is the error number
34.$! stores the error message
35.$" is the separator
36.$# is the default format
37.$(dollar), is the separator
38.$MATCH = $&
39.$SIG{__DIE__}
40.$SIG{__WARN__} = 'IGNORE';
41.$SIG{__WARN__} = sub {die "Warning: $_[0]"};
42.$\ is 'END_OF_OUTPUT'
43.$^ is the format header
44.$^O stores the name of the operating system
45.$^S: is inside eval
46.$^W: Check the '-w switch'
47.$^X: get the Perl execuatable file name
48.$_ for print function
49.$_ stores the user input
50.$~ is the format
51.%INC values
52.File-searching program using $ARGV.
53.Get Computer Name key in the %ENV
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64.Perl 5 Built-In Variables
65.Perl's modules reside in the directories named in the @INC array, or subdirectories
66.Perl's special arrays
67.Perl's special variables
68.Postmatch $'
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70.Print all command line argument
71.Print the default variable's ($_) value
72.Quick Sum
73.Read and set environment variables?
74.Read lines from supplied filenames
75.Reference element in @_
76.Resetting array base
77.Retrieving the Entire Pattern: $&
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80.Special Variables
81.System variables that control how write sends output to a file
82.Test of open and die with $!.
83.The $_ Scalar Variable
84.The @* field
85.The @ISA Array and Calling Methods
86.The Argument Vector @ARGV
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88.The Substitution Operator and $_
89.The code executes a line of code you type as long as that line doesn't start with a #
90.The environment associative array: Associative arrays %ENV holds your system's environment variables.
91.The following functions and operators work with the $_ variable by default:
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95.Using $, to set the separator for print command
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100.Using @_ directly
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102.Using eof and <> together.
103.Using the $. variable.
104.Using the $;(dollar and semicolon) variable.
105.Using the @_ to reference the parameter
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127.undef $/;