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Numbers (numeric constants) do not require quotation. Perl will convert numbers into strings and vice versa depending on the context in which they are used. When strings are converted into numbers, trailing non-numeric parts of the strings are discarded. If no leading part of a string is numeric, the string will be converted to the number 0.
Perl is particularly noted for its regular expression use, [21] and many other languages and applications implement Perl compatible regular expressions. Some languages such as Perl and Ruby support string interpolation, which permits arbitrary expressions to be evaluated and included in string literals.
Perl, like sed before it, solves this problem by allowing many other characters to be delimiters for a regular expression. For example, the following three examples are equivalent to the expression given above: m{ftp://[^/]*/pub/} m#ftp://[^/]*/pub/# m!ftp://[^/]*/pub/! Or this common translation to convert backslashes to forward slashes:
Perl is a highly expressive programming language: source code for a given algorithm can be short and highly compressible. [17] [18] Perl gained widespread popularity in the mid-1990s as a CGI scripting language, in part due to its powerful regular expression and string parsing abilities.
String functions are used in computer programming languages to manipulate a string or query information about a string (some do both).. Most programming languages that have a string datatype will have some string functions although there may be other low-level ways within each language to handle strings directly.
COBOL uses the STRING statement to concatenate string variables. MATLAB and Octave use the syntax "[x y]" to concatenate x and y. Visual Basic and Visual Basic .NET can also use the "+" sign but at the risk of ambiguity if a string representing a number and a number are together. Microsoft Excel allows both "&" and the function "=CONCATENATE(X,Y)".
Eval is understood to be the step of converting a quoted string into a callable function and its arguments, whereas apply is the actual call of the function with a given set of arguments. The distinction is particularly noticeable in functional languages , and languages based on lambda calculus , such as LISP and Scheme .
A string literal or anonymous string is a literal for a string value in the source code of a computer program. Modern programming languages commonly use a quoted sequence of characters, formally "bracketed delimiters", as in x = "foo" , where , "foo" is a string literal with value foo .