2013-09-11 42 views
2

我的老师要我们(在最下方),以显示我们在格式化方法值,但问题是,我们有一个子和她没有告诉我们如何使用它,我的老师是小于很有帮助。任何意见或帮助将不胜感激。我该如何使用System.out.printf?

public class SphereCalculations 
{ 
public static void main(String[] args) 
{ 
    //define variables 
    double circumference = 0; 
    double area = 0; 
    double volume = 0; 
    double surfacearea = 0; 
    double radius = 0; 
    Scanner scan = new Scanner (System.in); 
    DecimalFormat dFmt = new DecimalFormat("0.0000"); 

    //prompt for radius 
    System.out.println("Enter the sphere's radius: "); 
    radius = scan.nextDouble(); 

    //calculate values 
    circumference = 2 * Math.PI * radius; 
    area = Math.PI * (Math.pow(radius, 2)); 
    volume = ((4/3) * Math.PI) * Math.pow(radius, 3); 
    surfacearea = (4 * Math.PI) * Math.pow(radius, 2); 

    //Display values with println and DecimalFormat 
    System.out.println("Using Println"); 
    System.out.println("The radius: " + radius); 
    System.out.println("Circumference: " + dFmt.format(circumference)); 
    System.out.println("Area: " + dFmt.format(area)); 
    System.out.println("Volume: " + dFmt.format(volume)); 
    System.out.println("Surface Area: " + dFmt.format(surfacearea)); 

    //Display values with format method 
    System.out.printf(); 
+0

ħ TTP://docs.oracle.com/javase/6/docs/api/java/io/PrintStream.html#printf(java.lang.String中,java.lang.Object中...) –

+2

的http://文档。 oracle.com/javase/tutorial/java/data/numberformat.html –

回答

5

这里的几个例子:

(输出被示出在嵌入注释双引号内)

注:System.out.format()= System.out.printf ()

import java.util.Calendar; 
import java.util.Locale; 

public class TestFormat { 

    public static void main(String[] args) { 
     long n = 461012; 
     System.out.format("%d%n", n);  // --> "461012" 
     System.out.format("%08d%n", n); // --> "00461012" 
     System.out.format("%+8d%n", n); // --> " +461012" 
     System.out.format("%,8d%n", n); // --> " 461,012" 
     System.out.format("%+,8d%n%n", n); // --> "+461,012" 

     double pi = Math.PI; 

     System.out.format("%f%n", pi);  // --> "3.141593" 
     System.out.format("%.3f%n", pi);  // --> "3.142" 
     System.out.format("%10.3f%n", pi); // --> "  3.142" 
     System.out.format("%-10.3f%n", pi); // --> "3.142" 
     System.out.format(Locale.FRANCE, 
         "%-10.4f%n%n", pi); // --> "3,1416" 

     Calendar c = Calendar.getInstance(); 
     System.out.format("%tB %te, %tY%n", c, c, c); // --> "May 29, 2006" 

     System.out.format("%tl:%tM %tp%n", c, c, c); // --> "2:34 am" 

     System.out.format("%tD%n", c); // --> "05/29/06" 
    } 
} 

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