Question

我在网上搜索如何转换数组中的两个特定元素，并且对于研究非常不吉利

package scanner;

import java.util.Scanner;

public class EmployeeInformation {

    static Scanner sc = new Scanner(System.in);

    static String[][] info = {{"09-001", "Ja Gb", "100", "10", },
                        {"09-002", "Justine", "200", "20", },
                        {"09-003", "Ja Ja", "150", "15", }};

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

        System.out.print("     - MENU -\n");
        System.out.print("A. Search Record\nB. Payroll Summary\n------------------\nEnter choice: ");
        String choice = null;
        choice = sc.nextLine();


        if (choice.equalsIgnoreCase("a")) {
            System.out.print("Enter Employee #: ");
            String EmpNum = sc.nextLine();
            SearchRecord(EmpNum);
        }
        else if (choice.equalsIgnoreCase("b")){
                PayrollSummary();
            }
        else {
            System.out.print("Invalid input.");
        }
    }

    private static void SearchRecord(String employeeNumber) {
        // TODO Auto-generated method stub

        String[] matchedRow = null;
        for (int i = 0; i < info.length; i++) {
            String[] oneRow = info[i];
                if (oneRow[0].equals(employeeNumber)) {
                    matchedRow = oneRow;
                    break;
                }
        }
        System.out.print("\nEmployee #:\tEmployee Name\tRate per Hour\tTotal Hours Worked\n");

        for (int i = 0; i < matchedRow.length; i++) {

            System.out.print(matchedRow[i] + "\t\t");
        }
    }

    private static void PayrollSummary() {

        System.out.println("\nEmployee #:\tEmployee Name\tRate per Hour\tTotal Hours Worked\tGross Pay");

        int intArr[] = new int[info.length];
        int r = 0;
        while ( r < info.length) {
            int c = 0;
            while ( c <= r ) {
                if ( c == 2 ) {
                    intArr[c] = Integer.parseInt(info[r][c]);
                if ( c == 3 ) {
                    intArr[c] = Integer.parseInt(info[r][c]);
                }
                }

                c++;
            // How do I multiply index 2 and 3 of Array info and store it in info[r][4]?    
            }

            r++;
        }



    }
}

...

Answer 1

为了将两个表示为字符串的值相乘，您必须先解析它们。

如果要将任意String解析为Integer，您应该记住，不可能解析某些字符串，例如“Justine”。您必须处理在这种情况下将抛出的NumberFormatException。

try{
    Integer myInt = Integer.parseInt(info[x][y]);
}catch(NumberFormatException e){
    // handle your exception
}

Answer 2

你可以这样做

class Testing  
{  
  public static void main(String[] args)  
  {  
    System.out.println(isNumeric("123"));  
    System.out.println(isNumeric("123.45"));  
    System.out.println(isNumeric("$123"));  
    System.out.println(isNumeric("123x"));  
  }  
  public static boolean isNumeric(String str)  
  {  
    try  
    {  
      double d = Double.parseDouble(str);  
    }  
    catch(NumberFormatException nfe)  
    {  
      return false;  
    }  
    return true;  
  }  
}

通过这种方式，您可以解析数组，如果它是NumberFormatException，则它不是数字。

将一些字符串元素转换为int

2 个答案: