Java Strings: “String s = new String(”silly“);”

Question

I\'m a C++ guy learning Java. I\'m reading Effective Java and something confused me. It says never to write code like this:

String s = new String(\"silly\");         


        

Answer 1

when they say to write

String s = "Silly";

instead of

String s = new String("Silly");

they mean it when creating a String object because both of the above statements create a String object but the new String() version creates two String objects: one in heap and the other in string constant pool. Hence using more memory.

But when you write

CaseInsensitiveString cis = new CaseInsensitiveString("Polish");

you are not creating a String instead you are creating an object of class CaseInsensitiveString. Hence you need to use the new operator.