The primitive data types prefixed with “u” are unsigned versions with the same bit sizes. Effectively, this means they cannot store negative numbers, but on the other hand they can store positive numbers twice as large as their signed counterparts. The signed counterparts do not have “u” prefixed. The limits for int (32 bit) are: … Read more
Why C++ doesn’t have support for unsigned floats is because there is no equivalent machine code operations for the CPU to execute. So it would be very inefficient to support it. If C++ did support it, then you would be sometimes using an unsigned float and not realizing that your performance has just been killed. … Read more
There’s no dedicated “character type” in C language. char is an integer type, same (in that regard) as int, short and other integer types. char just happens to be the smallest integer type. So, just like any other integer type, it can be signed or unsigned. It is true that (as the name suggests) char … Read more
The fact that primitives are signed in Java is irrelevant to how they’re represented in memory / transit – a byte is merely 8 bits and whether you interpret that as a signed range or not is up to you. There is no magic flag to say “this is signed” or “this is unsigned”. As … Read more
Java does not have a datatype for unsigned integers. You can define a long instead of an int if you need to store large values. You can also use a signed integer as if it were unsigned. The benefit of two’s complement representation is that most operations (such as addition, subtraction, multiplication, and left shift) … Read more
This is from an interview with Gosling and others, about simplicity: Gosling: For me as a language designer, which I don’t really count myself as these days, what “simple” really ended up meaning was could I expect J. Random Developer to hold the spec in his head. That definition says that, for instance, Java isn’t … Read more
%lu is the correct format for unsigned long. Sounds like there are other issues at play here, such as memory corruption or an uninitialized variable. Perhaps show us a larger picture?
Unsigned can hold a larger positive value and no negative value. Yes. Unsigned uses the leading bit as a part of the value, while the signed version uses the left-most-bit to identify if the number is positive or negative. There are different ways of representing signed integers. The easiest to visualise is to use the … Read more
For iterating backwards see this answer. Iterating forwards is almost identical. Just change the iterators / swap decrement by increment. You should prefer iterators. Some people tell you to use std::size_t as the index variable type. However, that is not portable. Always use the size_type typedef of the container (While you could get away with … Read more