Search results
Results from the WOW.Com Content Network
For function that manipulate strings, modern object-oriented languages, like C# and Java have immutable strings and return a copy (in newly allocated dynamic memory), while others, like C manipulate the original string unless the programmer copies data to a new string.
Language feature comparison (part 2) Directives [Note 1] Conditionals Atomic groups [Note 2] Named capture [Note 3] Comments Embedded code Unicode property support [4] Balancing groups [Note 4] Variable-length look-behinds [Note 5] Boost.Regex: Yes Yes Yes Yes Yes No Some [Note 6] No No Boost.Xpressive: Yes No Yes Yes Yes No No No No CL-PPCRE ...
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)".
Note that "truth" is interpreted very differently by the string-based #if function and the numerically oriented functions #expr and #ifexpr. A string is considered true if it contains at least one non-whitespace character (thus, for example, the #if function interprets the strings "0" and "FALSE" as true values, not false).
If control exits the function without a return value having been explicitly specified, the function returns the default value for the return type. Sub Main(««ByVal »args() As String») instructions
A parsing expression is a kind of pattern that each string may either match or not match.In case of a match, there is a unique prefix of the string (which may be the whole string, the empty string, or something in between) which has been consumed by the parsing expression; this prefix is what one would usually think of as having matched the expression.
However, parser generators for context-free grammars often support the ability for user-written code to introduce limited amounts of context-sensitivity. (For example, upon encountering a variable declaration, user-written code could save the name and type of the variable into an external data structure, so that these could be checked against ...
Like raw strings, there can be any number of equals signs between the square brackets, provided both the opening and closing tags have a matching number of equals signs; this allows nesting as long as nested block comments/raw strings use a different number of equals signs than their enclosing comment: --[[comment --[=[ nested comment ...