A scalar value may be:
| nnn nn .nnnn .nnEnn |
Any integer or real decimal constant. | |
0xnn |
Hexadecimal constant. | |
0nn |
Octal constant. | |
0bnn |
Binary constant. | |
'text' |
String literal: only \' and \\ escape sequences are expanded. |
|
"text" |
String literal: all \x escape sequences and all $variable values are expanded. |
A scalar variable is named $identifier. It may contain:
| number | A floating point number (note that Perl does not use integer values). See Operators. | |
| or | ||
| string | A text string, of arbitrary length. See Operators. | |
| or | ||
undef |
The undefined value. Equivalent to zero when used in a numeric
expression, or an empty string when used in a string expression. Explicitly
check for undef using the defined(scalar expression) function. |