Java while循环跳过用户输入的第一次迭代

55ooxyrt  于 2023-05-12  发布在  Java
关注(0)|答案(1)|浏览(107)

我正在做一个游戏,现在我需要为“英雄”设置名字!这需要玩家输入英雄的名字。问题是,当它在控制台中询问英雄1的名字时,它只是跳过,直接跳到英雄2。如果我使用.next()而不是.nextLine(),它可以工作,但它会将任何带有空格的名称解释为两个不同的名称!
下面是代码,希望有意义!提前谢谢大家:)

public void heroNames() //sets the name of heroes
{
    int count = 1;
    while (count <= numHeroes)
    {
        System.out.println("Enter a name for hero number " + count);
        String name = scanner.nextLine(); 
        if(heroNames.contains(name)) //bug needs to be fixed here - does not wait for user input for first hero name
        {
            System.out.println("You already have a hero with this name. Please choose another name!");
        }
        else
        {
            heroNames.add(name);
            count++; //increases count by 1 to move to next hero
        }
    }
}
x6yk4ghg

x6yk4ghg1#

如果你用Scanner.nextInt读取numHeroes,一个换行符会留在它的缓冲区中,因此后面的Scanner.nextLine会返回一个空字符串,实际上会导致两个连续的Scanner.nextLine()序列来获得第一个英雄名字。
在下面的代码中,我建议你用Integer.parseInt(scanner.nextLine)读取英雄的数量,并且作为一种风格,不要使用局部变量count,因为它隐式地绑定到heroNames集合的大小:

Scanner scanner = new Scanner(System.in);
List<String> heroNames = new ArrayList<>();

int numHeroes;

System.out.println("How many heroes do you want to play with?");

while (true) {
    try {
        numHeroes = Integer.parseInt(scanner.nextLine());
        break;
    } catch (NumberFormatException e) {
        // continue
    }
}

while (heroNames.size() < numHeroes) {
    System.out.println("Type hero name ("
            + (numHeroes - heroNames.size()) + "/" + numHeroes + " missing):");
    String name = scanner.nextLine();
    if (heroNames.contains(name)) {
        System.out.println(name + " already given. Type a different one:");
    } else if (name != null && !name.isEmpty()) {
        heroNames.add(name);
    }
}

System.out.println("Hero names: " + heroNames);

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