Question

    //getFirstName method
    public String getFirstName()
    {
        String firstName = name.substring(0, name.lastIndexOf(' '));
        return firstName;
    }

    //getLastName method
    public String getLastName()
    {
        String lastName = name.substring(name.lastIndexOf(" ")+1);
        return lastName;
    }

    //alphaName method :: returns a String of the users's full name
    //in alphanumeric order;  returns a String with first and last named switched,
    //only if necessary; instance variable name is left unchanged
    // use the String class compareTo() method
    public String alphaName()
    {
        String compare = firstName.compareTo(lastName);
        if(compare < 0){
            return getFirstName() + getLastName();
        }
        else if(compare > 0){
            return getLastName() + getFirstName();
        }
        else{
            return getLastName() + getFirstName();
        }
        return compare;
    }

您好，我无法弄清楚如何按字母数字顺序编写代码。我现在有这个，并且不能正确输出。我没有添加整个程序，但这应该足够了。我使用了compare，抓住了方法getFirstName和getLastName，但输出不正确。请帮忙，谢谢！

Answer 1

compareTo应该返回一个整数，而不是字符串-您正尝试将其存储到字符串而不是整数中。将其更改为“ int compare”，它应该可以工作。

Answer 2

尝试一下-

public String alphaName(String firstName, String lastName)
{
    int compare = firstName.compareTo(lastName);
    if(compare < 0){
        return firstName + " " + lastName;
    }
    else if(compare > 0){
        return lastName + " " + firstName;
    }
    else{
        return lastName + " " + firstName;
    }
}

compareTo用于字母数字顺序问题中的字符串

2 个答案: