Perl Learning Note One

Scalar data

Scalar: number, character. Can be stored in the scalar volume or read from files and devices.

Numbers: All numbers have the same internal format-double-precision floating-point numbers.

Floating-point Direct amount: The number that the programmer typed directly into the program.

Integer direct volume: 61298040283768==61_298_040_283_768;

Operation:

String: There is no limit to the length of the string.

usr UTF8;

string literals within single quotation marks: all characters in single quotation marks represent themselves, except for single and backslash characters.

string literals within double quotation marks:

String operator: Connection operation. The special string repetition operator--x.

"Fred" x 3== "fredfredfred".

Perl built-in warning function: Use warning, or $perl-W my_program or #!/usr/bin/perl-w.

A more detailed description of the problem: use diagnostics; A brief warning message and detailed diagnostic instructions are listed in the PERLDIAG documentation.

Perl Learning Note One