They are in fact standard in C++, as defined by the ISO 14882:2003 C++ standard 2.5/2 (and, indeed, as defined by the 1998 edition of the standard). Note that they are built into the language itself and don’t require that you include a header file of some sort. However, they are very rarely used, and … Read more
<> should be preferred, all things being equal, since it accords with the sql standard and is technically more portable… != is non-standard, but most db’s implement it. sql:2008 grammar: <not equals operator> ::= <>
in C (and other languages probably) a single | or & is a bitwise comparison. The double || or && is a logical comparison. Edit: Be sure to read Mehrdad’s comment below regarding “without short-circuiting” In practice, since true is often equivalent to 1 and false is often equivalent to 0, the bitwise comparisons can … Read more
+ is implemented in java compilers. The compiler replaces String + String with either compile time constants or StringBuilder code. Note that this applies to primitives too. i.e, int i=1+2 could get directly replaced to int i=3 during compilation itself.
yes, it’s two nots. !!a is 1 if a is non-zero and 0 if a is 0 You can think of !! as clamping, as it were, to {0,1}. I personally find the usage a bad attempt to appear fancy.
This is fine, but it’s a lot more readable IMHO to call the base-class by name: Base::operator = (rhs);
The & operator performs logical “and” operation for bool operands and is not short circuited. It’s not a sequence point. You cannot rely on the order of evaluation of the operands. However, it’s guaranteed that both operands are evaluated. I do not recommend doing this. Using temporary variables is a better solution. Don’t sacrifice readability … Read more
^ is the xor operator. ** is exponentiation. 2**3 = 8
x = x++; is equivalent to int tmp = x; x++; x = tmp;
What you are talking about is a unary plus. It is different than the plus that is used with string concatenation or addition. If you want to use a unary plus to convert and have it added to the previous value, you need to double up on it. > 3 + 4 + “5” “75” … Read more