String formatting in Java

Question

I've been using python too much lately and I forget if there's a way to do this in Java:

print "I am a %s" % string

I googled, but it's hard to find simple stuff like this when you don't know exactly what this is called in each language.

Answer 1

System.out.println( "I am a " + string );

But I prefer this:

System.out.println( String.format( "I am a %s", string ) );

Answer 2

Two possible simple ways of doing it:

String yourStringHere = "human";
System.out.println(String.format("I am a %s", yourStringHere));

or

System.out.printf("I am a %s\n", yourStringHere);

Notice that the printf() will not print a newline, so you have to add it manually ("\n"). But (thanks to BalusC), you can also use "%n" in your format. It will be replaced by the default system newline character. (So: String.format("I am a %s%n", yourString))
Both prints I am a human\n.

In Java, it is called formatting. Take also a look at String.format().

Answer 3

You can use MessageFormat.format() to do this, but of instead %s you should use {0} (in this case).

System.out.print(MessageFormat.format("I am a {0}", string));

If you ever want to localize your program, this is the better way (or worse, depending on what you want to achieve), because it will use localized number formats automatically.