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What will be the output of the code?
❌ A. false true false true
❌ B. true true true true
❌ C. false false true true
❌ D. false false false true
✅ E. false true true true
❌ F. Error
❌ G. None of the above
Explanation:
1. String Pool and `intern()` Method:
- In Java, string literals (e.g., `"Hello, World!"`) are stored in the string pool.
- The intern() method returns a canonical representation for the string object. If the pool already contains a string equal to the current string object, the string from the pool is returned.
2. Line 1: `System.out.println(str1 == str2);`:
- str1 is a string literal stored in the string pool.
- str2 is a new string object created using the new keyword, so it is not in the string pool.
- The comparison == checks if both references point to the same object. Since str1 and str2 are different objects, the result is false.
3. Line 2: `System.out.println(str1 == str3);`:
- str3 is assigned directly to str1, so both references point to the same object in the string pool.
- Therefore, the result of str1 == str3 is true.
4. Line 3: `System.out.println(str1 == str4);`:
- str4 is str2.intern(), which returns the reference from the string pool.
- Since str1 is already in the string pool and str4 is now the interned version of str2, both point to the same object.
- Thus, str1 == str4 is true.
5. Line 4: `System.out.println(str1 == str5);`:
- str5 is the result of string concatenation using literals "Hello, " and "World!". This concatenation is resolved at compile time, and the resulting string is stored in the string pool.
- Since str1 is "Hello, World!" and str5 is also "Hello, World!" stored in the pool, str1 == str5 is true.
Output:
false
true
true
true
Correct Answer: E
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