这个JavaScript问题是否可能没有循环?

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.

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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