Remember that negative numbers are stored as the two’s complement of the positive counterpart. As an example, here’s the representation of -2 in two’s complement: (8 bits) 1111 1110 The way you get this is by taking the binary representation of a number, taking its complement (inverting all the bits) and adding one. Two starts … Read more
As always with these questions, the JLS holds the answer. In this case §15.26.2 Compound Assignment Operators. An extract: A compound assignment expression of the form E1 op= E2 is equivalent to E1 = (T)((E1) op (E2)), where T is the type of E1, except that E1 is evaluated only once. An example cited from §15.26.2 […] the following code is … Read more
? can mean a lot of different things in different contexts. Following a normal regex token (a character, a shorthand, a character class, a group…), it means “Match the previous item 0-1 times”. Following a quantifier like ?, *, +, {n,m}, it takes on a different meaning: “Make the previous quantifier lazy instead of greedy … Read more
Get the methods with Type.GetMethods, then use MethodInfo.IsSpecialName to discover operators, conversions etc. Here’s an example: using System; using System.Reflection; public class Foo { public static Foo operator +(Foo x, Foo y) { return new Foo(); } public static implicit operator string(Foo x) { return “”; } } public class Example { public static void … Read more
It is the modulo (or modulus) operator: The modulus operator (%) computes the remainder after dividing its first operand by its second. For example: class Program { static void Main() { Console.WriteLine(5 % 2); // int Console.WriteLine(-5 % 2); // int Console.WriteLine(5.0 % 2.2); // double Console.WriteLine(5.0m % 2.2m); // decimal Console.WriteLine(-5.2 % 2.0); // … Read more
Python uses the classic Algorithm D from Knuth’s ‘The Art of Computer Programming’. The running time is (generally) proportional to the product of lengths of the two numbers. Space is proportional to the sum of the lengths of the two numbers. The actual division occurs in Objects/longobject.c, see x_divrem(). For background on the internal representation … Read more
i += 4; means i = i + 4; // increase i by 4. While i =+ 4; is equivalent to i = +4; // assign 4 to i. the unary plus is effectively no-op. (See http://docs.oracle.com/javase/specs/jls/se7/html/jls-15.html#jls-15.15.3 for what a unary + does.)
There is no difference. For evidence see the C99 specification (section 6.7.5.3.8). “A declaration of a parameter as ‘‘function returning type’’ shall be adjusted to ‘‘pointer to function returning type’’, as in 6.3.2.1.”
AFAIK, there’s no such thing in MATLAB. And this is understandable(look at Steven Lord’s answer, post 11). That post indicates that since MATLAB is array based, such operator would be ambiguous and unintuitive, at best.
a |= b; is the same as a = (a | b); It calculates the bitwise OR of the two operands, and assigns the result to the left operand. To explain your example code: for (String search : textSearch.getValue()) matches |= field.contains(search); I presume matches is a boolean; this means that the bitwise operators behave … Read more