Answers for "String builder example in java 8"

java string builder

StringBuilder stringBuilder = new StringBuilder();

stringBuilder.append("string");

System.out.println("String = " + stringBuilder.toString());

why string builder

StringBuilder is for, well, building strings.
Specifically, building them in a very
performance way. The String class is good
for a lot of things, but it actually has
really terrible performance when assembling 
a new string out of smaller string parts
because each new string is a totally new,
reallocated string.