There are a lot of misconceptions here, both in the question itself and in the several answers. Let me begin by examining the premise of the question. The question is “why do we need the new keyword in C#?” The motivation for the question is this fragment of C++: MyClass object; // this will create … Read more
This is Brad Cox. My original answer misunderstood the question. I assumed reallyFast was a hardcoded extension to trigger faster messaging, not a kind of syntactic sugar. The real answer is that Smalltalk didn’t support it, perhaps because its parser couldn’t deal with the (assumed) ambiguity. Although OC’s square brackets would remove any ambiguity, I … Read more
Dim originally (in BASIC) stood for Dimension, as it was used to define the dimensions of an array. (The original implementation of BASIC was Dartmouth BASIC, which descended from FORTRAN, where DIMENSION is spelled out.) Nowadays, Dim is used to define any variable, not just arrays, so its meaning is not intuitive anymore.
Like puts (which sounds similar), it is designed to work with lines, using the \n character. gets takes an optional argument that is used for “splitting” the input (or “just reading till it arrives). It defaults to the special global variable $/, which contains a \n by default. gets is a pretty generic method for … Read more
From MSDN: In string concatenation operations, the C# compiler treats a null string the same as an empty string, but it does not convert the value of the original null string. More information on the + binary operator: The binary + operator performs string concatenation when one or both operands are of type string. If … Read more
Try C#7’s Pattern Matching. Using your example: if (new StringBuilder(“test”) is var sb && sb != null) { Console.WriteLine(sb); }
You can use local variables in extended assembly, but you need to tell the extended assembly construct about them. Consider: #include <stdio.h> int main (void) { int data1 = 10; int data2 = 20; int result; __asm__( ” movl %[mydata1], %[myresult]\n” ” imull %[mydata2], %[myresult]\n” : [myresult] “=&r” (result) : [mydata1] “r” (data1), [mydata2] “r” … Read more
I’m not an expert on the commas, but I know that standard Pascal was very persnickity about semi-colons being statement separators, not terminators. That meant you had to be very very careful about where you put one if you didn’t want to get yelled at by the compiler. Later Pascal-esque languages (C, Modula-2, Ada, etc.) … Read more
‘for backwards compatibility’ seems a sufficient reason for the type erasure of class generic types – it is needed e.g. to allow you to return an untyped List and pass it to some legacy code. The extension of this to generic methods seems like a tricky sub-case. The JLS snippet from 4.8 (which you quote) … Read more
Function style casts bring consistency to primitive and user defined types. This is very useful when defining templates. For example, take this very silly example: template<typename T, typename U> T silly_cast(U const &u) { return T(u); } My silly_cast function will work for primitive types, because it’s a function-style cast. It will also work for … Read more