如何控制Java中格式化文本的对齐方式？

Question

I'm knocking my head here using System.out.printf and I really don't understand something that seems that it should be much more simple.

public class main{
    public static void main(String args[]){
        double dog  = 3.85;
        double cat = 333.85;
        System.out.printf("Hola:%7.1f\n",dog);
        System.out.printf("Hola:%5.0f", cat);
    }
}

I'm trying to understand what the significance is of the numbers after the percentage symbol. In short in the line:

System.out.print("Number: %x.y", someNumber);

what does the x tell me and what does the y tell me?

Answer 1

• x = minimum width of how many digits are displayed to the left of the decimal with padding.
• y = precision of floating point numbers to the right of the decimal.