Question

我正在尝试从控制台获取字符串输入并将它们存储在ArrayList中。之后，我将添加所有输入的数字以获得总和我不明白我做错了什么，请建议

package mysmallprograms;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.Scanner;

/**   
 * my project to build a calculator
 *
 */    
public class Calculator {

    public static int add(ArrayList<String> numbers)
    {
        int sum=0;
        System.out.println("inside function add");
        if(numbers.isEmpty()==true) {
            System.out.println("empty string");
            return sum;
        } else {
            System.out.println("String arraylist to be summed");
            Iterator<String> it=numbers.iterator();

            while(it.hasNext()) {
                int elem=Integer.parseInt(( it.next()));
                sum+=elem;
                System.out.println("calculating sum");
                return sum;                     
            }

            return sum;
        }                               
    }

    public static void main(String[] args) {
        // TODO Auto-generated method stub

        Scanner input= new Scanner(System.in);
        ArrayList<String> numbers= new ArrayList<String>();
        System.out.println("enter the numbers you want to add press enter after every number:");

        try {
            while(input.hasNextLine()) {
                String s=input.nextLine();

                if(s.equals("*")) {   
                    System.exit(0);
                    input.close();                          
                } else {   
                    System.out.println("adding element in arraylist");
                    numbers.add(s);
                }                   
            }
        } catch(Exception e) {
            System.out.println(e);
        } finally {                             
            System.out.println("calling calculator ");
            int sum=add(numbers);
            System.out.println("Sum of numbers : "+sum);
        }
    }       
}

我正在尝试从控制台获取字符串输入并将它们存储在ArrayList中。之后，我将添加所有输入的数字以获得总和我不明白我做错了什么，请建议

Answer 1

package mysmallprograms;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Scanner;



/**

 * my project to build a calculator
 *
 */

    public class Calculator {
        public static int add(ArrayList<String> numbers)
        {   int sum=0;
            System.out.println("inside function add");
            if(numbers.isEmpty()==true)
                {System.out.println("empty string");
               }
            else
                {
                 System.out.println("String arraylist to be summed");
                 Iterator<String> it=numbers.iterator();

                 while(it.hasNext())
            {   int elem=Integer.parseInt(( it.next()));
                sum+=elem;
                System.out.println("calculating sum");
            }
        }
    return sum;

    }

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input= new Scanner(System.in);
        ArrayList<String> numbers= new ArrayList<String>();
        System.out.println("enter the numbers you want to add press enter after every number:");
        int num = Integer.parseInt(input.nextLine());
    try {
        while(num > 0 )
        { num--;
          String s=input.nextLine();
          System.out.println("adding element in arraylist");
          numbers.add(s);
        }
    }
       catch(Exception e) {
             System.out.println(e);
       }
        finally
        {
        System.out.println("calling calculator ");
        int sum=add(numbers);
        System.out.println("Sum of numbers : "+sum);
        }
    }


}

对不起，我还没有修复缩进。你的while循环在无限循环中运行，也做了一些其他的小改动。希望它有所帮助，干杯！

我的程序终止了

1 个答案: