Search results
Results from the WOW.Com Content Network
Sometimes, particularly in object-oriented programming, the comparison raises questions of data types and inheritance, equality, and identity. It is often necessary to distinguish between: two different objects of the same type, e.g., two hands; two objects being equal but distinct, e.g., two $10 banknotes
In C++, the C++20 revision adds the spaceship operator <=>, which returns a value that encodes whether the 2 values are equal, less, greater, or unordered and can return different types depending on the strictness of the comparison. [3] The name's origin is due to it reminding Randal L. Schwartz of the spaceship in an HP BASIC Star Trek game. [4]
Strings are passed to functions by passing a pointer to the first code unit. Since char * and wchar_t * are different types, the functions that process wide strings are different than the ones processing normal strings and have different names. String literals ("text" in the C source code) are converted to arrays during compilation. [2]
Tests if two strings are equal. See also #Compare and #Compare. Note that doing equality checks via a generic Compare with integer result is not only confusing for the programmer but is often a significantly more expensive operation; this is especially true when using "C-strings".
The practice of always using references in place of copies of equal objects is known as interning. If interning is used, two objects are considered equal if and only if their references, typically represented as pointers or integers, are equal. Some languages do this automatically: for example, Python automatically interns short strings. If the ...
The same distinction holds for comparing objects for equality: most basically there is a difference between identity (same object) and equality (same value), corresponding to shallow equality and (1 level) deep equality of two object references, but then further whether equality means comparing only the fields of the object in question or ...
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)".
The detailed semantics of "the" ternary operator as well as its syntax differs significantly from language to language. A top level distinction from one language to another is whether the expressions permit side effects (as in most procedural languages) and whether the language provides short-circuit evaluation semantics, whereby only the selected expression is evaluated (most standard ...