Question

Once the String object is created , we can’t modify it But if we do any operations on it JVM will create New Object. Here by creating new objects then JVM consumes more memory. Then i think it causes to memory issue right.?

Answer 1

You are correct. It is definitely worth being aware of this issue, even if it doesn’t affect you every time.

As you say, Strings cannot change after creation – they’re immutable and they don’t expose many ways to change them.

However, operations such as a split() will be generating additional string objects in the background, and each of those strings have a memory overhead if you are holding onto references to them.

As the other posters note, the objects will be small and garbage collection will usually clean up the old ones after they have gone out of scope, so you generally won’t have to worry about this.

However, if you’re doing something specific and holding onto large amounts of string references then this could bite you.

Look at String interning depending on your use case, noting the warnings on the linked page.

Two things to note:

1) Hard coded String literals will be automatically interned by Java, reducing the impact of this.

2) The + operator is more efficient in this regard, it will use String Builders underneath giving performance & memory benefits.