【发布时间】:2017-06-15 21:27:01
【问题描述】:
我需要实现一个接口,作为我 Java 课程的期末作业的一部分。被覆盖的界面应该打印一条短消息,描述一名足球运动员如何庆祝在 NFL 中被选中,如下所示:
System.out.println("name dances to celebrate his draft");
但是,当我将消息放入允许用户将玩家添加到他们的花名册的方法中时,我的界面没有打印消息。这是程序中重写的接口:
//Overridden celebrate method
@Override
public void celebrate(int i, int place){
int randomInteger;
if (place == 0) //Player is offensive
{
randomInteger = random1Thru6();
//players() is a method that contains all the players in the team
//'place' refers to the players location in the array of players on the team
switch (randomInteger)
{
case 1: System.out.println(players(i).get(place) + " dances to celebrate his draft!");
break;
case 2: System.out.println(players(i).get(place) + " cartwheels to celebrate his draft!");
break;
case 3: System.out.println(players(i).get(place) + " throws a party to celebrate his draft!");
break;
case 4: System.out.println(players(i).get(place) + " sings to celebrate his draft!");
break;
case 5: System.out.println(players(i).get(place) + " gets root beer for everyone to celebrate his draft!");
break;
case 6: System.out.println(players(i).get(place) + " gets donuts to celebrate his draft!");
}
}
else if (place == 1) //Player is defensive
{
randomInteger = random1Thru6();
switch (randomInteger)
{
case 1: System.out.println(players(i).get(place) + " dances to celebrate his draft!");
break;
case 2: System.out.println(players(i).get(place) + " cartwheels to celebrate his draft!");
break;
case 3: System.out.println(players(i).get(place) + " throws a party to celebrate his draft!");
break;
case 4: System.out.println(players(i).get(place) + " sings to celebrate his draft!");
break;
case 5: System.out.println(players(i).get(place) + " gets root beer for everyone to celebrate his draft!");
break;
case 6: System.out.println(players(i).get(place) + " gets pizza to celebrate his draft!");
}
}
}
我应该对进攻和防守位置有一种不同的庆祝反应,如上面的代码所示。 下面是引用的 random1Thru6() 方法:
public int random1Thru6() { //used to get a random number from 1 to 6
int randomInteger = (int)Math.random() * 10;
//this is supposed to call the method over and over again until it gives a number from 1-6 but it has been printing 7-9 as well
if (randomInteger > 6)
random1Thru6();
return randomInteger;
}
这里是 player() 方法:
//holds and prints all the players
public ArrayList<String> players(int i) {
ArrayList<String> returnedList = new ArrayList<>();
// Christian McCaffrey is a Running Back, Corn Elder is a Corner Back for the Carolina Panthers
ArrayList<String> Players1 = new ArrayList<String>();
Players1.add("Christian McCaffrey");
Players1.add("Corn Elder");
//Jake Butt is a Tight End, Brendan Langley is a Corner Back for the Denver Broncos
ArrayList<String> Players2 = new ArrayList<String>();
Players2.add("Jake Butt");
Players2.add("Brendan Langley");
//Ryan Switzer is a Wide Receiver, Taco Charlton is a Defensive End for the Dallas Cowboys
ArrayList<String> Players3 = new ArrayList<String>();
Players3.add("Ryan Switzer");
Players3.add("Taco Charlton");
//Dalvin Cook is a Running Back, Ifeadi Odenigbo is a Defensive Line for the Minnesota Vikings
ArrayList<String> Players4 = new ArrayList<String>();
Players4.add("Dalvin Cook");
Players4.add("Ifeadi Odenigbo");
switch (i)
{
case 1: returnedList.addAll(Players1);
break;
case 2: returnedList.addAll(Players2);
break;
case 3: returnedList.addAll(Players3);
break;
case 4: returnedList.addAll(Players4);
break;
}
return returnedList;
}
以下是celebrate() 方法的调用方式:
for (int l = 0; l < players(i).size(); l++)
{
if (choosePlayer.equalsIgnoreCase(players(i).get(l)))
{
addPlayer(players(i).get(l));
celebrate(i, l);
enterRoster();
}
}
还有:
addPlayer(players(i).get(place));
celebrate(i, place);
enterRoster();
addPlayer(int i, int place) 是一种将队伍“i”的队员在队伍队员数组中“place”位置的队员添加到用户名册的ArrayList中的方法。
注意:我按照评论中的建议检查了 random1Thru6() 调用了什么号码,现在我明白为什么它没有打印庆祝消息,因为我有 (int)Math.random() * 10 它总是返回 0 所以我改变了它到:
double randomDouble = Math.random() * 10;
int randomInteger = (int)randomDouble;
现在它会打印庆祝消息,但 random1Thru6() 现在返回所有数字 1-9,请解释我如何使此方法递归调用自身,直到它返回数字 1-6。
谢谢你的评论!
注意:我已经接受了如下所示的delephin的回答,谢谢大家的帮助!
【问题讨论】:
-
除了在默认方法的情况下,接口不做任何事情。听起来您正在编写一个可能实现接口的类。你能澄清一下吗?
-
@CollinD 谢谢,我已经编辑了我的问题。我希望它可以简化问题。
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没有足够的代码来提供帮助。没有打印任何内容的潜在原因:1)您没有调用该方法。 --- 2)
place的值不是 0 或 1。 --- 3)random1Thru6()返回值超出范围 1-6。 --- 我们可以提供的最佳帮助是:What is a debugger and how can it help me diagnose problems? -
向我们展示您如何调用此方法以及如何为交换机生成随机数。
-
打印方法的输入,以及random1Thru6()返回的值