How to format a double in Java?

To format a double in Java, use String.format.

Here's how you do it:

double aDouble = 1234.56789;

// 1,234.57
System.out.println(String.format("%,.2f", aDouble));

// 1234.57
System.out.println(String.format("%.2f", aDouble));

// 1234.6
System.out.println(String.format("%.1f", aDouble));