获取数组中对象内部元素的键

Question

我有一个数组，它有键并且在一个对象内。尝试获取数组内元素的键。当我搜索 4512 时，我应该得到 Eggs_code 密钥。const items = {  storeItems: {    milk_code: [1212, 9898, 1214],    vegetables_code: [2222, 75674, 8943, 3452],    eggs_code: [4543, 4512, 1754, 9090]  }}if (items.storeItems.includes(4512)) {  const type = Object.keys(items(4512);  console.log(type);}

Answer 1

在此：

const search_q = 4512;

let k = null;

const items = {

  storeItems: {

    milk_code: [1212, 9898, 1214],

    vegetables_code: [2222, 75674, 8943, 3452],

    eggs_code: [4543, 4512, 1754, 9090]

  }

}

Object.keys(items.storeItems).forEach(item => {

  if(items.storeItems[item].includes(search_q))

      k = item;

})

console.log(k)

Answer 2

用途Object.entries及find方法

const items = {

  storeItems: {

    milk_code: [1212, 9898, 1214],

    vegetables_code: [2222, 75674, 8943, 3452],

    eggs_code: [4543, 4512, 1754, 9090],

  },

};

const getKey = (obj, val) =>

  Object.entries(obj)

    .find(([key, arr]) => arr.includes(val))

    ?.shift();

    

    

console.log(getKey(items.storeItems, 4512));

Answer 3

您可以编写一个小函数来为您完成此操作。该函数在第一次找到代码时进行匹配。

const items = {

  store_items: {

    milk_code: [1212, 9898, 1214],

    vegetables_code: [2222, 75674, 8943, 3452],

    eggs_code: [4543, 4512, 1754, 9090]

  }

}

function find_code( code, object ) {

  for( const property in object )

    if( object[property].includes(code) ) return property;

  

  return undefined;

}

console.log( find_code( 4512, items.store_items ) );

console.log( find_code( 1200, items.store_items ) );

console.log( find_code( 8943, items.store_items ) );

请注意，您正在迭代 an Object，而不是Array. for..of您可以使用或迭代对象for..in。我使用了for..in，因为它默认提取属性名称。

Answer 4

您需要迭代 的键/值对storeItems，搜索值以返回键

const findKey = (obj, search) => {

  for (let [ key, val ] of Object.entries(obj)) {

    if (val.includes(search)) return key

  }

  return null

}

const items = {

  storeItems: {

    milk_code: [1212, 9898, 1214],

    vegetables_code: [2222, 75674, 8943, 3452],

    eggs_code: [4543, 4512, 1754, 9090]

  }

}

console.info(findKey(items.storeItems, 4512))

这将返回找到的第一个具有匹配值的键（按定义顺序）。

如果该值可以出现在多个值中并且您想要返回所有匹配项，则可以使用简单的过滤器

const findKeys = (obj, search) => {

  return Object.keys(obj).filter(key => obj[key].includes(search))

}

const items = {

  storeItems: {

    milk_code: [1212, 9898, 1214, 4512], // added 4512 here

    vegetables_code: [2222, 75674, 8943, 3452],

    eggs_code: [4543, 4512, 1754, 9090]

  }

}

console.info(findKeys(items.storeItems, 4512))