We have to build Strings all the time for log output and so on. Over the JDK versions we have learned when to use StringBuffer (many appends, thread safe) and StringBuilder (many appends, non-thread-safe).
What’s the advice on using String.format()? Is it efficient, or are we forced to stick with concatenation for one-liners where performance is important?
e.g. ugly old style,
String s = "What do you get if you multiply " + varSix + " by " + varNine + "?";
vs. tidy new style (String.format, which is possibly slower),
String s = String.format("What do you get if you multiply %d by %d?", varSix, varNine);
Note: my specific use case is the hundreds of ‘one-liner’ log strings throughout my code. They don’t involve a loop, so StringBuilder is too heavyweight. I’m interested in String.format() specifically.
