javascript - 搜索嵌套对象并返回对第一个找到的函数的引用，未知大小，未知名称

Question

我看到很多人询问如何在对象中查找对象，因此我想制作一个模块，可以搜索 JSON 对象并查找它是否具有键或该属性并返回对该属性的引用。

到目前为止我已经:

• 查找键和/或属性是否存在

我不知道如何搜索未知大小和形状的嵌套对象，如果它找到该键值的函数，则返回对其的引用，以便可以调用它。

/*
    @param Object
    @param String, Number, Bool, Type...
    Return a unknown position in an unknown
    nested Object with an unknown size or structure
    a function.
 */
function search(o, q) {
    Object.keys(o).forEach(function (k) {
        if (o[k] !== null && typeof o[k] === 'object') {
            search(o[k]);
            return;
        }
        /* Need e.g. */
        if (typeof k === 'function' || typeof o[k] === 'function') {
            // If functions object name is four, return reference
            return o[k] // Return function() { console.log('Four') } reference
            // We could use return o[k][0] for absolute reference, for first function
        }
        if (k === q || o[k] === q) {
            (k === q) ? console.log(`Matching Key: ${k}`) : console.log(`Matching Value: ${o[k]}`)
        }
        return o[k];
    });
}

let data = {
    1: 'One',
    'Two': {
        'Three': 'One',
    }, 
    'Four': function() {
        console.log('We successfully referenced a function without knowing it was there or by name!');
    }
};

search(data, 'One');
// I would like to also
let Four = search(data, 'Four'); // We might not know it's four, and want to return first function()
// E.g. Four.Four()

但话又说回来，我们不知道“四”会是关键。这时我们可以使用 if 语句 if typeof 函数来获取值。但我似乎无法正确返回它来执行该函数，特别是如果我们只是在不知道 key 的情况下返回我们找到的第一个函数。

Answer 1

您可以将引用和键作为单个对象返回 - 即函数的返回值将是 {foundKey: someValue}。然后您可以确定 someValue 是否是一个可以调用的函数。例如:

function search(o, q) {
  for (k in o) {
      if (k === q) return {[k]: o[k]}  // return key and value as single object
      if (o[k] !== null && typeof o[k] === 'object') {
          let found =  search(o[k], q)
          if (found) return found
      }       
  }
}

let data = {
  1: 'One',
  'Two': {'Three': 'One',}, 
  'Four': function() {
      console.log('We successfully referenced a function without knowing it was there or by name!')
  }
}

let searchKey = "Four"
let found = search(data, searchKey);

console.log("Found Object", found)

// is it a function? if so call it
if (typeof found[searchKey] == 'function'){
  found[searchKey]()
}

如果您只是对查找第一个函数感兴趣，您可以在边界情况下测试它并返回它。然后，您需要在尝试调用该函数之前测试该函数是否返回未定义:

function firstFuntion(o) {
  for (k in o) {
      if (typeof o[k] == 'function') return o[k]
      if (o[k] !== null && typeof o[k] === 'object') {
          let found = firstFuntion(o[k]);
          if (found) return found
      }  
  };
}

let data = {
  1: 'One',
  'Two': {
      'Three': 'One',
  }, 
  'Four': function() {
      console.log('We successfully referenced a function without knowing it was there or by name!');
  }
};

let found = firstFuntion(data);

// firstFuntion should return a function or nothing
if (found) found()