How do I append a newline character for all lines except the last one?

Question

I'm iterating through a HashMap (see my earlier question for more detail) and building a string consisting of the data contained in the Map. For each item, I will have a new line, but for the very last item, I don't want the new line. How can I achieve this? I was thinking I could so some kind of check to see if the entry is the last one or not, but I'm not sure how to actually do that.

Thanks!

Answer 1

Change your thought process from "append a line break all but the last time" to "prepend a line break all but the first time":

boolean first = true; StringBuilder builder = new StringBuilder();  for (Map.Entry<MyClass.Key,String> entry : data.entrySet()) {     if (first) {         first = false;     } else {         builder.append("\n"); // Or whatever break you want     }     builder.append(entry.key())            .append(": ")            .append(entry.value()); } 

Answer 2

one method (with apologies to Jon Skeet for borrowing part of his Java code):

StringBuilder result = new StringBuilder();  string newline = "";   for (Map.Entry<MyClass.Key,String> entry : data.entrySet()) {     result.append(newline)        .append(entry.key())        .append(": ")        .append(entry.value());      newline = "\n"; }