Explanation/Reference:
Explanation:
StringBuilder(int capacity)
Constructs a string builder with no characters in it and an initial capacity specified by the capacity argument.
Note: An instance of a StringBuilder is a mutable sequence of characters.
The principal operations on a StringBuilder are the append and insert methods, which are overloaded so as to accept data of any type. Each effectively converts a given datum to a string and then appends or inserts the characters of that string to the string builder. The append method always adds these characters at the end of the builder; the insert method adds the characters at a specified point.
Incorrect answers:
StringBuilder sb = new String("128");
StringBuilder not String is required.
setCapacity or getInstance do not work.