我是Java的新手,但是正在阅读《 Java:如何编程》(第9版)一书,并举了一个例子,在我的一生中,我无法弄清楚问题出在哪里。
这是教科书中源代码示例的(略)增强版本:
import java.util.Scanner; public class Addition { public static void main(String[] args) { // creates a scanner to obtain input from a command window Scanner input = new Scanner(System.in); int number1; // first number to add int number2; // second number to add int sum; // sum of 1 & 2 System.out.print("Enter First Integer: "); // prompt number1 = input.nextInt(); // reads first number inputted by user System.out.print("Enter Second Integer: "); // prompt 2 number2 = input.nextInt(); // reads second number from user sum = number1 + number2; // addition takes place, then stores the total of the two numbers in sum System.out.printf( "Sum is %d\n", sum ); // displays the sum on screen } // end method main } // end class Addition
我收到“NoSuchElementException”错误:
NoSuchElementException
Exception in thread "main" java.util.NoSuchElementException at java.util.Scanner.throwFor(Scanner.java:838) at java.util.Scanner.next(Scanner.java:1461) at java.util.Scanner.nextInt(Scanner.java:2091) at java.util.Scanner.nextInt(Scanner.java:2050) at Addition.main(Addition.java:16) Enter First Integer:
我知道这可能是由于源代码中的某些内容与Scannerfrom中的类不兼容所致java.util,但是在推断出问题所在的方面,我确实无法获得更多的帮助。
Scannerfrom
java.util
NoSuchElementException 被nextElement枚举方法抛出以指示枚举中没有更多元素。
nextElement
http://docs.oracle.com/javase/7/docs/api/java/util/NoSuchElementException.html
这个怎么样 :
if(input.hasNextInt() ) number1 = input.nextInt(); // if there is another number else number1 = 0; // nothing added in the input