When "abc" == new String("abc") Returns true (Yes, Really)

Umadevi R

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Jun 3, 2025

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🧠 The JVM’s String Pool is Weird — And You Can Hack It

Ask any Java dev:

System.out.println("abc" == new String("abc")); // true or false?

Everyone will say: false, because new String("abc") creates a new object on the heap.

But what if I told you… with a little trick, you can make it return true?

🧪 The Trick: Interning Dynamically Created Strings

public class StringHack {
    public static void main(String[] args) {
        String s1 = "abc";
        String s2 = new String("abc").intern();
        System.out.println(s1 == s2); // true 🤯
    }
}

By calling .intern() on s2, you're telling the JVM:

“Hey, put this string in the intern pool and return the pooled reference.”

Since "abc" is already there as a string literal, intern() returns the exact same reference.

🔍 What’s the Java String Pool?

• It’s a special area in memory for unique, immutable string literals
• Ensures memory efficiency by reusing identical String objects
• Only works automatically for compile-time constants

String a = "hello";      // goes into pool
String b = "he" + "llo"; // compiler optimizes, still pooled
String c = new…