Java class type variables

In java, there is a variable called the class type, which is different from the method for storing the value of the basic type variable. Both basic variables and class variables are implemented as a memory location. However, because the amount of memory required for the basic variables is the same, the system can set a fixed space for the variables to keep the named object. Variables of the class type are different. Due to its uncertain length, it is difficult for the system to allocate a fixed space to save the variables of the named object. Therefore, for a class type variable, it stores the memory address of the object rather than the object itself. The following is an example:

/*** Comments: special instance for assigning values between classes * @ author plug-in name * Create Time: 2013-09-12 **/public class StringTest {private String str; public String getStr () {return str;} public void setStr (String str) {this. str = str;} public static void main (String [] args) {StringTest str1 = new StringTest (); StringTest str2 = new StringTest (); str1.setStr ("111111 "); str2.setStr ("222222"); // value assignment between class types, which is to assign the memory address of str1 to str2. After the value is assigned, it points to the same memory address str2 = str1; str2.setStr ("333333"); System. out. println (str1.getStr (); // The output result is 333333 System. out. println (str2.getStr (); // The output result is 333333 }}

From the output, we can see that the class type variable does not simply store the assigned value in the naming object, but stores the address in the class type variable. Therefore, the value assignment statement between class variables assigns the memory address, and the last two variables point to the same address.

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