String object in java

Question

As we know String is immutable, which means a new instance is created every time.

My question is that if I write:

System.out.println("Java"+"is"+"programming");

then how many objects are created in pool?

Answer 1

Your example will create a single string object in the string pool.

after that, if you do:

String x = "Javaisprogramming";

it will still point to the same object in the string pool. You can read more here

Answer 2

Your example will create a single string object. This is noted throughout the Java documentation.

The way I understand it, Java only adds new strings to the string pool when they're initially created. So,

String str1 = "hello";

Would be a single string in the pool.

So would

String str2 = "Java" + "is" + "cool";

Answer 3

Your Example will create 'single' string only which is

String x = "Javaisprogramming";

because '+' is a string concatenation operator in java(it internally call append()) so when you call System.out.println("Java"+"is"+"programming"); then compiler create one string object from concatenation and send it with println() method.

for more about '+' operator see this answer