Best way to concatenate List of String objects? [duplicate]

Answer 1

Rather than depending on ArrayList.toString() implementation, you could write a one-liner, if you are using java 8:

String result = sList.stream()
                     .reduce("", String::concat);

If you prefer using StringBuffer instead of String since String::concat has a runtime of O(n^2), you could convert every String to StringBuffer first.

StringBuffer result = sList.stream()
                           .map(StringBuffer::new)
                           .reduce(new StringBuffer(""), StringBuffer::append);