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Working with Numbers and Strings in Perl |
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In Perl, numbers and strings are called scalars. Scalars that do not change during the lifetime of a program are known as constants or literals. Scalars that do change are known as variables. Operators do something with scalars, for example, add together the contents of two variables. Literals/ConstantsThere are two types of literal:
Numeric literals may be integers, for example, 6, floating point, for example, 12.5, or scientific notation, for example, 2e10. Strings are a sequence of characters, for example, goodbye cruel world. Scalar VariablesData that may change during the lifetime of a program is stored in variables, for example, $total. The dollar ($) sign is called a type identifier, and tells Perl that the variable contains scalar data. Variable names can contain alphanumeric characters (a-z, A-Z, and 0-9) and the underscore character, and are case-sensitive. Expressions and OperatorsPerl programs are collections of expressions and statements that, by default, are executed in the order in which they appear in the program.
1. #!/usr/bin/perl -w The equals sign (=) is known as the assignment operator. It takes the value on its right-hand side, and puts it in the variable on the left. The star (*) is the multiplication operator. Two stars together (**) indicate 'to the power of'. Another example:
1. $a="Goodbye"; The dot (.) concatenates the contents of variables $a and $b, and the result is put into variable $c. Author: Backrubber Go back to Perl Tutorials home page Go back to Tutorials home page
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