javascript - 我怎样才能运行一段代码直到得到相同的结果 3 次？

Question

如何让这段代码运行直到连续获得 3 个“蓝色”卷？

var cards = ['Blue', 'Yellow'];
var currentCard = 'Yellow';
while (currentCard !== 'Blue') {
  console.log(currentCard);
  var randomNumber = Math.floor(Math.random() * 2);
  currentCard = cards[randomNumber]
}
console.log('Blue')

Answer 1

您可以只使用一个变量来计算蓝色已经滚动了多少次，然后在达到该数量时停止

如果你希望它在你得到黄色时重置，就像你在下面的评论中所说的那样，添加一个 else 来重置计数 :)

I need a block that increases a variable each time I get a blue card and when you get a yellow card you reset it

const cards = ['Blue', 'Yellow'];
let currentCard = 'Yellow',
    blueCount = 0;

while (blueCount < 3) {
  const randomNumber = Math.floor(Math.random() * 2);
  console.log(currentCard);
  currentCard = cards[randomNumber];

  if (currentCard === 'Blue') {
    blueCount++;
  } else {
    blueCount = 0;
  }
}

console.log('Blue')

您可以在没有 while 循环的情况下完成此操作，也可以使用递归。我下面的功能不是处理它的最佳方式，但应该给你一个想法

var cards = ['Blue', 'Yellow'];

function recursiveRoll3(max = 3, target = 'Blue', count = 0, card = getRandomCard()) {
  if (count === max) return;

  console.log(card)

  return card === target ?
     recursiveRoll3(max, target, count += 1) :
     recursiveRoll3(max, target);
}

function getRandomCard() {
  return cards[Math.floor(Math.random() * 2)];
}

console.log('Find 3 blue rolls then stop')
recursiveRoll3()
console.log('Find 1 yellow roll then stop')
recursiveRoll3(1, 'Yellow')

这是一个使用 es6 类的完全顶级版本，希望任何人都应该能够阅读并猜测发生了什么。

class RollTimes {
  constructor({ max = 0, target = null, possibilities = [] }) {
    this.max = max;
    this.target = target;
    this.possibilities = possibilities;
    
    this.count = 0;
    this.currentCard = null;
  }
  
  roll() {
    while (this.notDone) {
      
      this.currentCard = this.getRandomCard();

      console.log(this.currentCard);
      
      this.count = this.hitTarget ? this.count + 1 : 0;
    }
  }

  get notDone() {
    return this.count < this.max;
  }
  
  get hitTarget() {
    return this.currentCard === this.target;
  }
  
  get randomNumber() {
    return Math.floor(Math.random() * this.possibilities.length);
  }
  
  getRandomCard() {
    return this.possibilities[this.randomNumber];
  }
}

const roller = new RollTimes({
  max: 3,
  target: 'Blue',
  possibilities: ['Blue', 'Yellow']
});

roller.roll();