what happens with new String(“”) in String Constant pool

Question

if i create a string object as

String s=new String(\"Stackoverflow\");

will String object created only in heap, or it also makes a copy in Str

Answer 1

My answer is YES!

Check the following code first:

String s0 = "Stackoverflow";
String s1 = new String("Stackoverflow");
String s2 = s1.intern();

System.out.println(s0 == s1);
System.out.println(s1 == s2 );
System.out.println(s0 == s2);

//OUTPUT:
false
false
true

s0 hold a reference in the string pool, while new String(String original) will always construct a new instance. intern() method of String will return a reference in the string pool with the same value.

Now go back to your question:

Will String object created only in heap, or it also makes a copy in String constant pool?

Since you already wrote a string constant "Stackoverflow" and pass it to your String constructor, so in my opinion, it has the same semantic as:

String s0 = "Stackoverflow";
String s1 = new String(s0);

which means there will be a copy in String constant pool when the code is evaluated.

But, if you construct the String object with following code:

String s = new String("StackoverflowSOMETHINGELSE".toCharArray(),0,13);

there won't be a copy of "Stackoverflow" in constant pool.