Why Can't I Use `new CaseInsensitiveString('Polish')` Like I Do With `new String('silly')`?

Clarifying Java String Creation: Revisiting "String s = new String("silly")"

In Java, the creation of String objects is a topic that often raises questions. One such question pertains to the difference in usage between String and other classes when assigning literals.

Why is "CaseInsensitiveString cis = new CaseInsensitiveString("Polish")" Correct?

The statement "CaseInsensitiveString cis = new CaseInsensitiveString("Polish")" is indeed correct because String is a unique class in Java. This behavior is not applicable to other classes, such as CaseInsensitiveString.

Understanding String's Special Behavior:

Unlike other classes, String has certain inherent characteristics that allow this unique behavior:

• String Literals are Automatically Interned: String literals (e.g., "Polish") are automatically interned into the JVM's string pool. This means that only one String object is created for each unique literal, regardless of how many times it is used.
• String Does Not Have a "Copy Constructor": String does not have a standard constructor that accepts a String as an argument. Instead, it has unique functionality that allows direct initialization from literals.

How to Make CaseInsensitiveString Behave Like String:

To make CaseInsensitiveString behave like String in this regard, you would need to override its constructor and manually intern the passed-in String literal into the string pool. This would require access to the JVM's internal string pool and could result in performance issues if not done carefully.

Conclusion:

In summary, String is a unique class in Java that allows for simplified initialization with literals. Other classes, such as CaseInsensitiveString, do not have this behavior and require explicit construction using their proper constructors.

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