· PERL – Syntax – Variables
- PERL has
only one type of variable, called scalar.
tutorial shows possible ways of loading scalar with constant number.
- Integers can be defind in
four different formats.
$a = 0b010110111111; #Binary format begins with zero followed by 'b' or 'B'.
$a = 02677; #Octal format begin with zero.
$a = 1471; #Decimal format.
$a = 0x5BF; #Hexadecimal format begins with zero followed by 'x'
- Decimal Numbers:
- Decimal numbers can be defind
in normal and exponantional form.
$a = 12345.67; #Normal form.
$a = 0.67;
$a = -.67;
$a = 12.23E-10; #Exponential form.
$a = 0.23E-10;
$a = -.23E-10;
- Underscores are ignored and
are used to make integers easier to read.
$a = 1_471_; #Integer.
$a = 0x_5B_F_; #Hexadecimal.
$a = 0b_01011_0111111_; #Binary.
$a = 0_2_677_; #Octal.
$a = 12_3.14_15_92; #Decimal.
$a = 1_2_.2_3_E-1_0_; #Decimal.
- Integers in base 10 and
decimal numbers are implicitly stored in memory as numbers if you use qoutes.
$a = "9"; #Same as 9.
$a = '9'; #Same as 9.
$a = 9;
- Integers in binary, octal or
hexadecimal form are NOT implicitly stored in memory as numbers if you use
To force such conversion you
can use functions hex and oct functions.
$a = hex(' AF'); #Convert from hex to base 10.
$a = hex('0xAF'); #Convert from hex to base 10.
$a = oct('0xAF'); #Convert from hex to base 10.
$a = oct('0257'); #Convert from octal to base 10.
$a = oct('0b10101111'); #Convert from binary to base 10.
- You can display scalar value by using print function.
print $a; #Integers are
displayed in base 10.