这个JavaScript问题是否可能没有循环? [英] Is this JavaScript problem possible without loops?

问题描述

当前在代码提交网站上，它不会让我继续前进.

Currently on a code submission website and it won't let me move forward.

使用此字符数组，将名称以"M"开头的每个字符打印到控制台.暂时不要使用任何循环.

Using this characters array, print to the console every character which name begins with ‘M’. Don’t use any kind of loop, yet.

var filmCharacters = [
       ['Vito', 'Michael', 'Sonny', 'Freddo'],
       ['Mia', 'Vincent', 'Jules', 'Butch'],
       ['Bella', 'Edward', 'Jacob', 'Carlisle'],
       ['James', 'M', 'Moneypenny', 'Felix']
];

我最近的尝试是

for (var i = 0; i < filmCharacters.length; i++) {
    for (var j = 0; j < filmCharacters[i].length; j++) {
        if (filmCharacters[i][j].startsWith('M')) {
            console.log(filmCharacters[i][j]);
        }
    }
}

推荐答案

一个 for 循环是一个循环.

如果您想使代码一目了然，我想从技术上讲，无需任何循环机制(例如递归)就可以做到:

If you wanted to make the code hard to understand at a glance, I suppose it would technically be possible to do so without any looping mechanism, such as with recursion:

var filmCharacters = [
        ['Vito', 'Michael', 'Sonny', 'Freddo'],
        ['Mia', 'Vincent', 'Jules', 'Butch'],
        ['Bella', 'Edward', 'Jacob', 'Carlisle'],
        ['James', 'M', 'Moneypenny', 'Felix']
];

const checkArr = arr => {
  if (arr.length) {
    checkSubarr(arr[0])
    checkArr(arr.slice(1));
  }
};
const checkSubarr = subarr => {
  if (subarr.length) {
    if (subarr[0].startsWith('M')) {
      console.log(subarr[0]);
    }
    checkSubarr(subarr.slice(1));
  }
};
checkArr(filmCharacters);

即使不允许这样做，我也认为代码确实很不错.

If even that isn't permitted, I suppose the code be really WET.

var filmCharacters = [
        ['Vito', 'Michael', 'Sonny', 'Freddo'],
        ['Mia', 'Vincent', 'Jules', 'Butch'],
        ['Bella', 'Edward', 'Jacob', 'Carlisle'],
        ['James', 'M', 'Moneypenny', 'Felix']
];
const c = filmCharacters;

const check = str => {
  if (str.startsWith('M')) console.log(str);
};
check(c[0][0]);
check(c[0][1]);
check(c[0][2]);
check(c[0][3]);

check(c[1][0]);
check(c[1][1]);
check(c[1][2]);
check(c[1][3]);

check(c[2][0]);
check(c[2][1]);
check(c[2][2]);
check(c[2][3]);

check(c[3][0]);
check(c[3][1]);
check(c[3][2]);
check(c[3][3]);

但这太荒谬了.

var filmCharacters = [
        ['Vito', 'Michael', 'Sonny', 'Freddo'],
        ['Mia', 'Vincent', 'Jules', 'Butch'],
        ['Bella', 'Edward', 'Jacob', 'Carlisle'],
        ['James', 'M', 'Moneypenny', 'Felix']
];

filmCharacters
  .flat()
  .filter(str => str.startsWith('M'))
  .forEach(x => console.log(x));

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