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String s = new String("abc");
String s1 = "abc";
String s2 = new String("abc");
System.out.println(s == s1);
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System.out.println(s == s.intern());   
System.out.println(s1 == s1.intern());   
System.out.println(s1.intern() == s2.intern());  
System.out.println(s == s.intern());
System.out.println(s1 == s1.intern());
System.out.println(s1.intern() == s2.intern());
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