What is the string pool in Java and what does intern() do?

Equal string literals share one object from the string pool. A string made with new is a separate object on the heap. intern() returns the pooled version.

public class Main {
    public static void main(String[] args) {
        String a = "java";
        String b = "java";
        String c = new String("java");
        String d = c.intern();

        System.out.println(a == b);       // same pooled object
        System.out.println(a == c);       // c is a different object
        System.out.println(a == d);       // intern gives the pooled one
        System.out.println("ja" + "va" == a);     // joined at compile time: pooled
    }
}

Always compare content with equals(). See Java Strings.

• Previous Interview Question
• Next Interview Question

---

Tutorials
No Content Found.

Exercises & Assignments
No Content Found.

Interview Questions & Answers
No Content Found.