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首先,感謝您的閱讀!我可以從超類對象數組中獲取子類變量嗎?
我做了一個「運動員」,這是「足球運動員」的超級類。 所以我做了一個Sportsman對象的數組,它也包含足球對象,這裏沒有問題(我對繼承的工作原理有一個很好的概念)。
我可以將特定於足球運動員的變量設置爲數組中的對象,但是當我要打印剛剛聲明給該對象的變量時,我無法調用get-methods,因爲該數組是一個Sportsman-array而不是一個足球運動員陣列。
所以這裏是我的問題:我如何從運動員超類數組中打印足球運動員特定變量?
事情要知: 我無法爲子類對象創建單獨的數組。他們必須混合! 雖然在超類對象的數組中放置了一個子類對象,但我明確地將其作爲子類對象。但是,我無法在其上使用子類方法。
主要代碼:
public class SportApp {
public static void main(String[] args)
{
Scanner input = new Scanner(System.in);
Sportsman[] sportArr = new Sportsman[10];
for(int count=0 ; count < sportArr.length ; count++)
{ System.out.println("Is the sportsman a footballer?");
String answer = input.nextLine();
System.out.println("Last name?");
String lastName = input.nextLine();
System.out.println("name?");
String name = input.nextLine();
switch (answer){
case "yes": System.out.println("Which club does he play in?");
String club = input.nextLine();
System.out.println("At what position?");
String pos = invoer.nextLine();
sportArr[count]=new Footballer(lastName,name,club,pos);
break;
default: System.out.println("What sport?");
String sport = input.nextLine();
sportArr[count]=new Sportsman(lastName,name,sport);
}
}
System.out.println("All sportsmen that don't play football:");
for(int count=0 ; count < sportArr.length ; count++)
{ if(!(sportArr[count] instanceof Footballer))
{ System.out.print("name: ");
sportArr[count].print();} }
System.out.println("All football players sorted by position:");
//Same as previous print, but with added player position and club!
for(int count=0 ; count < sportArr.length ; count++)
{ if(sportArr[count] instanceof Footballer)
{
/*what I've tried:
*System.out.println("front players:");
*if(sportArr[count].getPos()=="front") //the .getPos doesn't work because it wants to invoke it on a Sportsman where getPos doesn't exist
*{ sportArr[count].print();} //as the problem above, it doesn't see the object is also a Footballer so it does the Sportsman print()
*
*I wanted to do a regular sportArr[count].pos to print the Position but even now it doesn't recognise the object as Footballer, so I can't see pos.
*/
}
}}}
鑄件確實解決了問題!太感謝了! –