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In computer science, type conversion, [1] [2] type casting, [1] [3] type coercion, [3] and type juggling [4] [5] are different ways of changing an expression from one data type to another. An example would be the conversion of an integer value into a floating point value or its textual representation as a string, and vice versa.
Unlike the bitset in C++, the Java BitSet does not have a "size" state (it has an effectively infinite size, initialized with 0 bits); a bit can be set or tested at any index. In addition, there is a class EnumSet , which represents a Set of values of an enumerated type internally as a bit vector, as a safer alternative to bit fields.
For example: 0101 (decimal 5) AND 0011 (decimal 3) = 0001 (decimal 1) The operation may be used to determine whether a particular bit is set (1) or cleared (0). For example, given a bit pattern 0011 (decimal 3), to determine whether the second bit is set we use a bitwise AND with a bit pattern containing 1 only in the second bit:
Bit fields can be used to reduce memory consumption when a program requires a number of integer variables which always will have low values. For example, in many systems, storing an integer value requires two bytes (16-bits) of memory; sometimes the values to be stored actually need only one or two bits.
The actual sizes of short int, int, and long int are available as the constants short max int, max int, and long max int etc. ^b Commonly used for characters. ^c The ALGOL 68, C and C++ languages do not specify the exact width of the integer types short , int , long , and ( C99 , C++11 ) long long , so they are implementation-dependent.
Fastest integer types that are guaranteed to be the fastest integer type available in the implementation, that has at least specified number n of bits. Guaranteed to be specified for at least N=8,16,32,64. Pointer integer types that are guaranteed to be able to hold a pointer. Included only if it is available in the implementation.
Although on GCC and LLVM this particular program compiles and runs as expected, more complicated examples may interact with assumptions made by strict aliasing and lead to unwanted behavior. The option -fno-strict-aliasing will ensure correct behavior of code using this form of type-punning, although using other forms of type punning is ...
However, on modern standard computers (i.e., implementing IEEE 754), one may safely assume that the endianness is the same for floating-point numbers as for integers, making the conversion straightforward regardless of data type. Small embedded systems using special floating-point formats may be another matter, however.