String 对象

\"abc\"

编译过程

使用intern方法，内存中会创建该对象，然后将对象的引用加入到常量池中

堆

栈

intern

 0: ldc #2 // String Andy 2: astore_1 3: ldc #3 // String 24 5: astore_2 6: ldc #4 // String Developer 8: astore_3 9: new #5 // class java/lang/StringBuilder 12: dup 13: invokespecial #6 // Method java/lang/StringBuilder.\"<init>\":()V 16: aload_1 17: invokevirtual #7 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder; 20: aload_2 21: invokevirtual #7 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder; 24: aload_3 25: invokevirtual #7 // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder; 28: invokevirtual #8 // Method java/lang/StringBuilder.toString:()Ljava/lang/String;

String str = new String(\"abc\");String str2 = \"hello\";

str

str2

常量池 “abc”\"hello\"

String a=\"abc\";String b=\"def\";String c=\"abcdef\";String d=a+b;System.out.println(c==d)创建了四个对象