Java 中的 Else-if 语句不起作用，我做错了什么？

Question

So I'm trying to do a simple code with an if-else-if statement, but it isn't working. I have only done if-else before and I am getting confused. Here is the code. Why isn't it accepting my else-if?

import java.util.Scanner;

public class DaysOfWeek {
public static void main (String[]args) {
    Double day;
    System.out.print("Enter the day: ");
    Scanner sc = new Scanner(System.in);
    day = sc.nextDouble();
    if (day.equals("Monday"));
    {
        System.out.println("Sounds like someone has a case of the Mondays!");
    }
    else if (day.equals("Wednesday"));
    {
        System.out.println("It's hump day! El ombligo!");
    }
    else if (day.equals("Friday"));
    {
        System.out.println("Finally. It's Friday!");
    }
    else {System.out.println("It's another day of the week.");}
}}

Answer 1

1. You want String day and sc.nextLine() if you want any comparison to work as written

2. if and else if lines should not use ; - Easier to see if you write like

    if (condition) { }

Answer 2

Thank-you everyone for quickly pointing out my semicolons at the end of my if-else-if lines. Also, thank-you for the catch on the string as opposed to double, I knew this part but had overlooked it because I was too frustrated with my confusion of the if-else-if lines. Once I corrected the two issues it worked exactly how I'd intended.

String day and sc.nextLine() replaced Double in order to make a proper comparison.

; was removed from the ends of my if-else-if lines.

I also added a little bit so that it would take various options for days entered

    import java.util.Scanner;

    public class DaysOfWeek{
    public static void main (String[]args) {
    String day;
    System.out.print("Enter the day: ");
    Scanner sc = new Scanner(System.in);
    day = sc.nextLine();
    if (day.equals("Monday")||day.equals("M")||day.equals("Mon.")||day.equals("Mon"))

    {
        System.out.println("Sounds like someone has a case of the Mondays!");
    }
    else if (day.equals("Wednesday")||day.equals("W")||day.equals("Wed.")||day.equals("Wed"))
    {
        System.out.println("It's hump day! El ombligo!");
    }
    else if (day.equals("Friday")||day.equals("F")||day.equals("Fri.")||day.equals("Fri"))
    {
        System.out.println("Finally. It's Friday!");
    }
    else {System.out.println("It's another day of the week.");}
}}

Answer 3

It has nothing to do with the else-if. You obtain a double input ( sc.nextDouble() ) and compare it with String afterwards. This will never be true, hence the else will always be called