无法添加我的整数以获得正确的输出

Question

所以我正在尝试做功课，这是问题：

编写一个程序，提示用户读取两个整数并显示其总和。如果将除整数以外的任何内容作为输入传递，则程序应捕获引发的 InputMismatchException，并通过打印"请输入整数"来提示用户输入另一个数字。

下面是示例运行和我应该测试的内容。

SAMPLE RUN #1: java InputMismatch
Enter an integer: 2.5↵ 
Please enter an integer↵ 
Enter an integer: 4.6↵ 
Please enter an integer↵ 
Enter an integer: hello!↵
Please enter an integer↵ 
Enter an integer:7↵ 
Enter an integer:5.6↵
Please enter an integer↵
Enter an integer:9.4↵ 
Please enter an integer ↵
Enter an integer:10↵ 
17↵

当我测试我的代码并输入整数时，它按预期工作，但是，当两个输入正确输入时，我坚持让整数相加。我做错了什么？

import java.util.InputMismatchException;
import java.util.Scanner;
public class TestInputMismatch {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int num1 = 0;
int num2 = 0;
boolean isValid = false;
while (!isValid) {
try {
System.out.print("Enter an integer: ");
int number = input.nextInt();
System.out.println("The number entered is " + number);
boolean continueInput = false;
}
catch (InputMismatchException ex) {
System.out.println("Try again. (" + "Incorrect input: an integer is required)");
input.nextLine();
}
} 
System.out.println((num1 + num2));
}
}

Answer 1

尝试在while中添加另一个条件并将数字放在数组中。

int[] numbers = new int[2];

并在您的 while 循环中更改此设置：

int count = 0;
while (!isValid && count <2) {
try {
System.out.print("Enter an integer: ");
numbers[count] = input.nextInt();
count++;
System.out.println("The number entered is " + number);
boolean continueInput = false;
}
catch (InputMismatchException ex) {
System.out.println("Try again. (" + "Incorrect input: an integer is required)");
input.nextLine();
}
} 

希望有帮助。

Answer 2

使用此方法进行检查：

public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int[] numArray = new int[2];
int count = 0;
while (count <= 1) {
try {
System.out.print("Enter an integer: ");
int number = input.nextInt();
System.out.println("The number entered is " + number);
numArray[count] = number;
count++;
} catch (InputMismatchException ex) {
System.out.println("Try again. (" + "Incorrect input: an integer is required)");
input.nextLine();
}
}
int num1 = numArray[0];
int num2 = numArray[1];
System.out.println((num1 + num2));
}

Answer 3

你需要把逻辑拼接在一起。当您采用 2 个数字 2 标志时，将确保您获得两个变量的正确输入。此外，这两个标志都确保您在发生异常时正确输入 num1 或 num2。 如果需要输入 n 个任意整数，则可能需要使用动态集合并将数字添加到集合中。

public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int num1 = 0;
int num2 = 0;
boolean num1Valid = false;
boolean num2Valid = false;
while (num1Valid==false || num2Valid==false) {
try {
if(num1Valid == false) {
System.out.print("Enter an integer for num1: ");
num1 = input.nextInt();
System.out.println("The number entered for num1 is " + num1);
num1Valid = true;
}
if(num2Valid == false) {
System.out.print("Enter an integer for num2: ");
num2 = input.nextInt();
System.out.println("The number entered for num2 is " + num2);
num2Valid = true;
}
}
catch (InputMismatchException ex) {
System.out.println("Try again. (" + "Incorrect input: an integer is required)");
input.nextLine();
}
}
input.close()
System.out.println((num1 + num2));
}

Answer 4

你需要捕获异常，在这种情况下你可以使用 e.getMessage((

public class TestInputMismatch {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int num1=0, number=0;
boolean isValid = false;
while (!isValid) {
try {
System.out.print("Enter an integer: ");
number = input.nextInt();
if(number > 0) {
System.out.println("The number entered is " + number);
}
num1 += number;
System.out.println("are would you like continue the program? Y or 
N ");
String condition = input.next();
if(condition.equalsIgnoreCase("Y")) {
isValid = false;
} else {
isValid = true;
}
}
catch (InputMismatchException ex) {
System.out.println(ex.getMessage());
System.out.println("You cannot type words");
isValid = true;
}
}
System.out.println("Result = " + num1);
input.close();
}
}

在另一种情况下，是否可以使用表达式语言的方法匹配

请参见以下示例：

if(valor.matches("[0-9]*"))

Answer 5

您可以在 try 块内添加两个数字

import java.util.InputMismatchException; import java.util.Scanner;

公共类 TestInputMismatch {

public static void main(String[] args( {

Scanner input = new Scanner(System.in);
int num1 = 0;
int num2 = 0;
boolean isValid = false;
while (!isValid) {
try {
System.out.print("Enter an integer: ");
num1 = input.nextInt();
System.out.print("Enter an integer: ");
num2 = input.nextInt();
System.out.println("The numbers you  entered are " + num1 + ","+num2);
int sum = num1+num2;
System.out.println("The sum Of the numbers you entered is: "+ sum);
boolean continueInput = false;
}
catch (InputMismatchException ex) {
System.out.println("Try again. (" + "Incorrect input: an integer is required)");
input.nextLine();
}
} 
System.out.println((num1 + num2));

} }

Answer 6

import java.util.Scanner;
import java.util.InputMismatchException;
public class InputMismatch {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int[] numArray = new int[2];
int count = 0;
while (count <= 1) {
try {
System.out.print("Enter an integer:");
int number = input.nextInt();
numArray[count] = number;
count++;
} catch (InputMismatchException e) {
System.out.println("Please enter an integer.");
input.nextLine();
}
}
System.out.println(numArray[0] + numArray[1]);

}
}