Question

我试图检查用户输入是否等于我的数组中的数据，然后打印与字符串数组对应的int数组，但是当我运行程序时什么都没有出现。

我做错了什么？

这是我主要方法中的所有内容：

  String firstname;
  String middleinitial;

  System.out.println("What is your first name?");
  firstname = myScan.nextLine();

  System.out.println("What is your middle initial?");
  middleinitial = myScan.nextLine();

 String[] firstNameLetter = {"A", "Albert", "Alice", "Ann", "Anna", "Annie",        "Arthur", 
            "B", "Bernard", "Bette", "Bettie", "Betty", "C", "Carl",
            "Catherine", "Charles", "Clara", "D", "Donald", "Dorothy, E",
            "Edward", "Elizabeth", "F", "Florence", "Frank", "G", "George",
            "Grace", "H", "Harold", "Harriet", "Harry", "Hazel", "Helen",      "Henry",
            "I", "J", "James", "Jane", "Jayne", "Jean", "John", 
            "Joan", "Joseph", "K", "L", "M", "Margaret", "Martin",
            "Marvin", "Mary", "Melvin", "Mildred", "N", "O", "P",
            "Patricia", "Paul", "Q", "R", "Richard", "Ruby", "Robert",
            "Ruth", "S", "T", "Thelma", "Thomas", "U", "V",
            "W", "Walter", "Wanda", "William", "Wilma", "X", "Y",
            "Z"};

    int[] firstNameNumber     = {000, 020, 020, 040, 040, 040, 040,
             060, 80, 80, 80, 80, 100, 120,
             120, 140, 140, 160, 180, 180, 200,
             220, 220, 240, 260, 260, 280, 300,
             300, 320, 340, 340, 360, 360, 380, 380,
             400, 420, 440, 440, 440, 460, 460,
             480, 480, 500, 520, 540, 560, 560,
             580, 580, 600, 600, 620, 640, 660,
             680, 680, 700, 720, 740, 740, 760,
             760, 780, 800, 820, 820, 840, 860,
             880, 900, 900, 920, 920, 940, 960,
             980};

String[] middleNameLetter = {" ", "A", "B", "C", "D", "E", "F",
             "G", "H", "I", "J", "K", "L", "M",
             "N", "O", "P", "Q", "R", "S", "T",
             "U", "V", "W", "X", "Y", "Z"};

int[] middleNameNumber    = {0, 1, 2, 3, 4, 5, 6,
                             7, 8, 9, 10, 11, 12, 13,
                             14, 14, 15, 15, 16, 17, 18,
                             18, 18, 19, 19, 19, 19};

for (int count = 0; count < firstNameLetter.length; count++)
{
    if (firstname.equals(firstNameLetter[count]))
    {
        System.out.println(firstNameNumber[count]);
    }
}

for (int count = 0; count < middleNameLetter.length; count++)
{
    if (middleinitial.equals(middleNameLetter[count]))
    {
        System.out.println(middleNameNumber[count]);
    }
}

Answer 1

当我自己运行这段代码时，所有人似乎都在工作。我认为你的逻辑没有错。你必须在那里有一个拼写错误。

public static void main(String[] args) {

    Scanner myScan = new Scanner(System.in);
    String firstname;
    String middleinitial;

    System.out.println("What is your first name?");
    firstname = myScan.nextLine();

    System.out.println("What is your middle initial?");
    middleinitial = myScan.nextLine();

    String[] firstNameLetter = {"A", "Albert", "Alice", "Ann", "Anna", 
        "Annie","Arthur", "B", "Bernard", "Bette", "Bettie", "Betty", 
        "C", "Carl", "Catherine", "Charles", "Clara", "D", "Donald", 
        "Dorothy, E", "Edward", "Elizabeth", "F", "Florence", "Frank", 
        "G", "George", "Grace", "H", "Harold", "Harriet", "Harry", "Hazel",
        "Helen", "Henry", "I", "J", "James", "Jane", "Jayne", "Jean", 
        "John", "Joan", "Joseph", "K", "L", "M", "Margaret", "Martin",
        "Marvin", "Mary", "Melvin", "Mildred", "N", "O", "P",
        "Patricia", "Paul", "Q", "R", "Richard", "Ruby", "Robert",
        "Ruth", "S", "T", "Thelma", "Thomas", "U", "V",
        "W", "Walter", "Wanda", "William", "Wilma", "X", "Y",
        "Z"};

    int[] firstNameNumber = {000, 020, 020, 040, 040, 040, 040,
                             060, 80, 80, 80, 80, 100, 120,120,
                             140, 140, 160, 180, 180, 200, 220, 
                             220, 240, 260, 260, 280, 300, 300,
                             320, 340, 340, 360, 360, 380, 380,
                             400, 420, 440, 440, 440, 460, 460,
                             480, 480, 500, 520, 540, 560, 560,
                             580, 580, 600, 600, 620, 640, 660,
                             680, 680, 700, 720, 740, 740, 760,
                             760, 780, 800, 820, 820, 840, 860,
                             880, 900, 900, 920, 920, 940, 960, 980};  

    String[] middleNameLetter = {" ", "A", "B", "C", "D", "E", "F",
                                 "G", "H", "I", "J", "K", "L", "M",
                                 "N", "O", "P", "Q", "R", "S", "T",
                                 "U", "V", "W", "X", "Y", "Z"};

    int[] middleNameNumber = {0, 1, 2, 3, 4, 5, 6,
                              7, 8, 9, 10, 11, 12, 13,
                              14, 14, 15, 15, 16, 17, 18,
                              18, 18, 19, 19, 19, 19};

    for (int count = 0; count < firstNameLetter.length; count++) {
        if (firstname.equals(firstNameLetter[count])) {
            System.out.println(firstNameNumber[count]);
        }
    }

    for (int count = 0; count < middleNameLetter.length; count++) {
        if (middleinitial.equals(middleNameLetter[count])) {
            System.out.println(middleNameNumber[count]);
        } 
    }
}

Answer 2

您可能想要尝试equalsIgnoreCase()而不是equals()，并且可能还想在for循环中添加break语句，以便在字符串匹配时停止迭代。

Answer 3

您可以将数组转换为列表并使用该方法。 list.contains() Arrays.asList（firstNameLetter）。载（姓名）;

所有给定输入的

等等

Answer 4

作为一项完整性检查，您是否能够成功重新编译？在尝试运行您的解决方案时，我发现Scanner实例未被声明。添加以下内容： Scanner myScan = new Scanner(System.in);

允许我使用以下输出运行：

$java ScannerTest
What is your first name?
Henry
What is your middle initial?
A
380
1

Answer 5

您的程序运行正常（除了您可能已经丢失并且没有重复的Scanner myScan = new Scanner(System.in);之外）。

你可能会感到困惑的是，你已经将几个整数定义为八进制值。当您开始一个0值的整数时，它被声明为八进制。

例如，对应于Albert的第二个值是020。这是16的八进制值。

正如其他人所提到的，您可能希望在字符串上使用equalsIgnoreCase()并在循环内使用break;。同样具有两个相等长度的阵列是危险的;更好地将值成对存储在HashMap或其他结构中。

Answer 6

if(str.toLowerCase().equals())

如何检查是否在数组中找到用户输入？

6 个答案: