参考
见以下代码:
package com.ljh.corejava;import java.util.ArrayList;import java.util.List;import java.util.Scanner;public class NextIntTest { public static void main(String[] args) { Scanner sc = new Scanner(System.in); List1、输入如下:students = new ArrayList () ; for(int i = 0 ; i < 3; i++){ Student s = new Student(); System.out.print("Enter name:"); s.name = sc.nextLine(); System.out.print("Enter number:"); s.number = sc.nextInt(); students.add(s); } for(Student s : students){ System.out.println(s.name+" : " + s.number); } }}class Student{ //学生名字 String name; //学号 int number;}
Enter name:ll
Enter number:1 Enter name:Enter number:kk Exception in thread "main" java.util.InputMismatchExceptionat java.util.Scanner.throwFor(Unknown Source)at java.util.Scanner.next(Unknown Source)at java.util.Scanner.nextInt(Unknown Source)at java.util.Scanner.nextInt(Unknown Source)at com.ljh.corejava.NextIntTest.main(NextIntTest.java:23)在nextLine()中读取了第一行ll,但nextInt()只读取了数字1却没有读取换行符,下一个nextLine()会读取换行符,再下一个nextInt()会读取k,因此出现了错误,类型不匹配。
解决方法一:
加一个nextLine()读取换行符,并不做处理。
Student s = new Student(); System.out.print("Enter name:"); s.name = sc.nextLine(); System.out.print("Enter number:"); s.number = sc.nextInt(); sc.nextLine(); students.add(s);
输出结果:
Enter name:ll
Enter number:1 Enter name:ll Enter number:1 Enter name:kk Enter number:2 ll : 1 ll : 1 kk : 2处理方法二:
使用nextLine()读取int类型后,再用Integer.parseInt()产生数字。
System.out.print("Enter name:"); s.name = sc.nextLine(); System.out.print("Enter number:"); //解决方法二: s.number = Integer.parseInt(sc.nextLine());