2015-12-02 25 views
0

我遇到了printf问题。我想打印出两个sepreate数组,并将小数位数限制为1,但是出现错误。 第一个阵列将以摄氏温度打印,第二个阵列将获得这些值并将其更改为Farenheit,并将其打印到屏幕上。我试图在打印出数字时实现printf方法。我能想到的唯一问题是我在数组中引用索引值,而不是实际上是双精度值。Printf不适用于双数阵列

import java.util.Scanner; 
public class tempOne { 
    public static void main (String [] args){ 
     Scanner sc = new Scanner(System.in); 
     double [] temp1 = new double [10]; 
     double [] temp2 = new double[10]; 
     System.out.println("Please enter 10 temperatures in Celsius: "); 

     for (int index = 0; index<temp1.length;index++)//Gets temperatures in Celsius. 
     { 
      temp1[index]=sc.nextDouble(); 
     } 

     for (int index = 0; index<temp1.length;index++)//Prints temperatures in Celsius. 
     { 
      System.out.printf("Temperatures in Celsius: %.1f", temp1[index] + " "); 
     } 

     for (int index = 0; index<temp1.length;index++)//Copies array 1 into array 2. 
     { 
      temp2[index]=temp1[index]; 
     } 

     System.out.println(""); 

     for (int index = 0; index<temp1.length;index++)//Changes values in array 2 to Farenheit. 
     { 
      temp2[index] = ((temp1[index]*9/5)+32); 
     } 

     for (int index = 0; index<temp1.length;index++) 
     { 
      System.out.printf("Temperatures in Farenheit: %.1f", temp2[index] + " ");//Prints array 2. 
     } 

    } 
} 

这里是结果:

Please enter 10 temperatures in Celsius: 
20.22 
Temperatures in Celsius: Exception in thread "main" java.util.IllegalFormatConversionException: f != java.lang.String 
    at java.util.Formatter$FormatSpecifier.failConversion(Formatter.java:4302) 
    at java.util.Formatter$FormatSpecifier.printFloat(Formatter.java:2806) 
    at java.util.Formatter$FormatSpecifier.print(Formatter.java:2753) 
    at java.util.Formatter.format(Formatter.java:2520) 
    at java.io.PrintStream.format(PrintStream.java:970) 
    at java.io.PrintStream.printf(PrintStream.java:871) 
    at tempOne.main(tempOne.java:16) 

任何人有怎么在这里上的任何想法?

回答

2

printf年代末取下+ " "

%.1f表示“打印一个小数点后的浮点值”,但+ " "表示您将该数字转换为String

+0

非常感谢! – Scoot

+0

@Scoot可以自由地接受这个作为答案,如果它帮助你 – Buddy

2

你想格式化double,而你传递String参数。尝试(删除+ ""):

System.out.printf("Temperatures in Farenheit: %.1f", temp2[index])