How does intern work in the following code?

Question

String a = \"abc\";
String b = a.substring(1);
b.intern();
String c = \"bc\";
System.out.println(b == c);

The question might be foolish as intern h

Answer 1

Look at the doc of String#intern() method

When the intern method is invoked, if the pool already contains a string equal to this String object as determined by the equals(Object) method, then the string from the pool is returned. Otherwise, this String object is added to the pool and a reference to this String object is returned.

Now follow the comments

    String b = a.substring(1);  // results "bc"
    b.intern();                 // check and places "bc" in pool
    String c = "bc";            // since it is a literal already presented in pool it gets the reference of it
    System.out.println(b == c);// now b and c are pointing to same literal