This is not an object, this is a character reference. C# uses virtual machines. Program composition (heap and stack). Put the object in the heap. The face value of the word put on the stack. The heap is recovered by garbage collection mechanism, and the stack is released after the program is executed. Heaps are allocated by programmers, such as objects. The data in the stack is allocated by the program itself, not by the programmer. It is compiled by a compiler and distributed at runtime. You can know whether it is the same object by looking at their hash values yourself. String a = " abcString b = " abca = = b；