difference between System.out.printf and String.format

Question

may i know what is the difference between the two in java? i am reading a book and it can either use both of it to display strings.

Answer 1

String.format returns a formatted string. System.out.printf also prints the formatted string.

Answer 2

String.format returns a new String, while System.out.printf just displays the newly formatted String to System.out, sometimes known as the console.

These two snippets of code are functionally equivalent:

String formattedString = String.format("%d is my favorite number", 42);
System.out.print(formattedString);

and

System.out.printf("%d is my favorite number", 42);

Answer 3

These two methods exhibit the exact same behavior. We can use the format(...) with String, Java.util.Formatter (J2SE 5) and also with PrintWriter.

Answer 4

The first one writes to the stdout and the second one returns a String object.

Which to use depends on the sole purpose. If you want to display the string in the stdout (console), then use the first. If you want to get a handle to the formatted string to use further in the code, then use the second.

Answer 5

String.format formats strings, doesn't display them. I think you mean System.out.println(String.format("......", ....)) or some similar construct ?