java - 出现无法解决的错误

Question

编译我的java程序后，我遇到了一堆错误，但我不知道如何解决它们。有人可以帮我吗？ =/

class Date{

    public static boolean isLeapYear(int year){
        boolean answer = false;

        if(year % 4 == 0  &&(year % 400 == 0 || year % 100 != 0))
            answer = true;  
        else 
            answer = false;

       return answer;
    }
}


int returnDaysInMonth (int year, int month){

if (month==1||month==3||month==5||month==7||month==8||month==10||month==12){

     return 31;

} else if (month==4||month==6||month==9||month==11){

     return 30;

} else if(isLeapYear(year)){

     return 29;
} else {
       return 28;

}
}

以下是编译错误:

/Users/vlop/NetBeansProjects2/JavaLibrary1/src/Date.java:22: class, interface, or enum expected
public int returnDaysInMonth (int year, int month){
/Users/vlop/NetBeansProjects2/JavaLibrary1/src/Date.java:28: class, 
interface, or enum expected
} else if (month==4||month==6||month==9||month==11){
/Users/vlop/NetBeansProjects2/JavaLibrary1/src/Date.java:32: class, 
interface, or enum expected
} else if(isLeapYear(year)){
/Users/vlop/NetBeansProjects2/JavaLibrary1/src/Date.java:35: class, 
interface, or enum expected
} else {
/Users/vlop/NetBeansProjects2/JavaLibrary1/src/Date.java:38: class, 
interface, or enum expected
}
5 errors

Answer 1

在类声明关闭后，您正尝试执行大量 Java 操作。

正确的缩进有助于识别此类问题:

class Date {
    public static boolean isLeapYear(int year) {
        boolean answer = false;

        if(year % 4 == 0  &&(year % 400 == 0 || year % 100 != 0))
            answer = true;
        else 
            answer = false;

        return answer;
    }
} // End of class.

// WAT
int returnDaysInMonth (int year, int month) {

// etc.

另外，单独的问题，但您可以直接返回 boolean 表达式的结果:

public static boolean isLeapYear(int year) {
    return ((year % 4 == 0) && ((year % 400 == 0) || (year % 100 != 0)));
}

即使您对此感到不舒服，您仍然可以避免一些噪音:

public static boolean isLeapYear(int year) {
    if (year % 4 == 0  &&(year % 400 == 0 || year % 100 != 0)) {
        return true;
    }
    return false;
}