String comparison confused

Question

Before we move on: I understand we should use .equals() to compare content. I am now just talking about if the actual references are the same for the following scenario.

Answer 1

The comparison works as follows:

String str1 = "str";`   //"str" is created in SCP and str1 is a reference to that    
String str2 = "string";` //"string" is created in SCP and str2 is a reference   
String str3 = "ing";`  //"ing" is created in SCP and str3 is a reference    
String str4 = str1 + str3;//"string" will be created on Heap and str4 is a reference (this is because if any string created at runntime will always be created on Heap) (here SCP already has this "string" so no change) make a note      that str4 is pointing to Heap string Object and not SCP   

str1 = str4; `// str1 and str4 will start pointing to same String Object on Heap    
String str5 = "string";`  // SCP already has this and str2 pointing to that so now onwards str5 will also point to it   

based on above    
1. str1 and str4 -- > are pointing to "string" object on heap    
2. str2 and str5 -- > are pointing to "string" object in scp  
3. str3 -- > is pointing to "ing" in scp   

and finally the corresponding output can be traced based on above lines:

System.out.println(str1==str2);`//false   
System.out.println(str1.intern()==str2.intern());`//true   
System.out.println(str1==str5);`//false   
System.out.println(str2==str5);`//true   
System.out.println("str"+"ing"=="string");`//true as "str"+"ing" will be replaced by "string" at compile time only (constant)