What is meant by immutable?

Question

This could be the dumbest question ever asked but I think it is quite confusing for a Java newbie.

1. Can somebody clarify what is meant by immutable? <

Answer 1

Immutable means that once the object is created, non of its members will change. String is immutable since you can not change its content. For example:

String s1 = "  abc  ";
String s2 = s1.trim();

In the code above, the string s1 did not change, another object (s2) was created using s1.