Question

I’ve seen something like this in code

somestring = "Today is {0}, tomorrow is {1}";

I know that it’ll put values into the string from another variable, but how do I do it?

Update: As there is several ways to achieve this effect, which way is the most effecient?

Answer 1

Have you looked at the MessageFormat documentation ?

e.g. (an example)

 Object[] arguments = {
     new Integer(7),
     new Date(System.currentTimeMillis()),
     "a disturbance in the Force"
 };

 String result = MessageFormat.format(
     "At {1,time} on {1,date}, there was {2} on planet {0,number,integer}.",
     arguments);

 output: At 12:30 PM on Jul 3, 2053, there was a disturbance
           in the Force on planet 7.

With respect to your question re. efficiency, I would only worry about this if you encounter performance issues and they relate to this. I would expect the above to be reasonably efficient – especially given there’ll likely be some output (to std. out or similar?) involved, which I’d expect to be a bigger bottleneck.