Unions P194 A single object can be referenced by using different data types The syntax of a union declaration is identical to that for structures, but its semantics are very different Rather than having the different fields reference different blocks of memory they all reference the same block syntax:语法 大 semantic:语义11 Unions P194 • A single object can be referenced by using different data types • The syntax of a union declaration is identical to that for structures, but its semantics are very different • Rather than having the different fields reference different blocks of memory, they all reference the same block *syntax: 语法 *semantic: 语义