Perl Language Interpolation in Perl What is interpolated
Example
Perl interpolates variable names:
my $name = 'Paul';
print "Hello, $name!\n"; # Hello, Paul!
my @char = ('a', 'b', 'c');
print "$char[1]\n"; # b
my %map = (a => 125, b => 1080, c => 11);
print "$map{a}\n"; # 125
Arrays may be interpolated as a whole, their elements are separated by spaces:
my @char = ('a', 'b', 'c');
print "My chars are @char\n"; # My chars are a b c
Perl does not interpolate hashes as a whole:
my %map = (a => 125, b => 1080, c => 11);
print "My map is %map\n"; # My map is %map
and function calls (including constants):
use constant {
PI => '3.1415926'
};
print "I like PI\n"; # I like PI
print "I like " . PI . "\n"; # I like 3.1415926
Perl interpolates escape sequences starting with \:
\t horizontal tab
\n newline
\r return
\f form feed
\b backspace
\a alarm (bell)
\e escape
Interpolation of \n depends on the system where program is working: it will produce a newline character(s) according to the current system conventions.
Perl does not interpolate \v, which means vertical tab in C and other languages.
Character may be addressed using their codes:
\x{1d11e} 𝄞 by hexadecimal code
\o{350436} 𝄞 by octal code
\N{U+1d11e} 𝄞 by Unicode code point
or Unicode names:
\N{MUSICAL SYMBOL G CLEF}
Character with codes from 0x00 to 0xFF in the native encoding may be addressed in a shorter form:
\x0a hexadecimal
\012 octal
Control character may be addressed using special escape sequences:
\c@ chr(0)
\ca chr(1)
\cb chr(2)
...
\cz chr(26)
\c[ chr(27)
\c\ chr(28) # Cannot be used at the end of a string
# since backslash will interpolate the terminating quote
\c] chr(29)
\c^ chr(30)
\c_ chr(31)
\c? chr(127)
Uppercase letters have the same meaning: "\cA" == "\ca".
Interpretation of all escape sequences except for \N{...} may depend on the platform since they use platform- and encoding-dependent codes.
