91104-一道题理解 String 常量池

判断题

• Java中 基本数据类型是引用传递 （false）===> java 不存在引用传递

填空题

• 阅读下面代码，填写合适的结果（JDK 8）

  选择填空
  rs1 = ()
  rs2 = ()
  rs3 = ()
  rs4 = ()
  A true  B false
  [1-4]={B,A,A,B}
  

public class StringPoolDemo {

    private static String str1 = "str1";
    private String str2 = "str3";

    public static void main(String[] args) {

        String str3 = new String("str1");
        str3.intern();
        String str4 = "str1";
        boolean rs1 = str3 == str4;
        System.out.println("rs1 ====> "+rs1);

        String str5 = new String("str1") + new String("str2");
        str5.intern();
        String str6 = "str1" + "str2";
        boolean rs2 = str5 == str6;
        System.out.println("rs2 ====> "+rs2);

        StringPoolDemo constantTest = new StringPoolDemo();
        String str7 = "str3";
        boolean rs3 = constantTest.str2 == str7;
        System.out.println("rs3 ====> "+rs3);

        String str8 =new String("java");
        str8.intern();
        String str9 = "java";
        boolean rs4 = str8==str9;
        System.out.println("rs4 ====> "+rs4);
    }
}