Lodash递归删除项目

Question

给定这个JSON对象,lodash如何reach从对象中删除值？

{ 
    total: 350,
    SN1: { 
        reach: 200,
        engagementRate: 1.35
    },
    SN2: {
        reach: 150,
        engagementRate: 1.19
    }
}

我一直试图迭代地删除()它但我总是得到一个未定义的对象作为回报所以我很肯定我做错了.这也是我第一次使用lodash,这可能是实际问题.

有人可以帮忙吗？

Answer 1

_.transform()将对象传递给另一个对象,并在将值传递给新对象时,检查该值是否为对象以及是否具有"reach"属性,如果是,则使用_.omit()获取新对象而不reach:

var obj = {
  total: 350,
  SN1: {
    reach: 200,
    engagementRate: 1.35
  },
  SN2: {
    reach: 150,
    engagementRate: 1.19
  }
};

var result = _.transform(obj, function(result, value, key) {
  result[key] = _.isObject(value) && `reach` in value ? _.omit(value, 'reach') : value;
});

console.log(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.15.0/lodash.min.js"></script>

如果你需要一个处理多个嵌套对象级别的递归解决方案,这里deepOmit使用相同的想法但没有_.omit,并且可以用来删除多个键(请参阅代码中的注释):

var obj = {
  total: 350,
  SN1: {
    reach: 200,
    engagementRate: 1.35,
    DEEP_SN1: {
      reach: 200,
      engagementRate: 1.35
    }
  },
  SN2: {
    reach: 150,
    engagementRate: 1.19
  }
};

function deepOmit(obj, keysToOmit) {
  var keysToOmitIndex =  _.keyBy(Array.isArray(keysToOmit) ? keysToOmit : [keysToOmit] ); // create an index object of the keys that should be omitted

  function omitFromObject(obj) { // the inner function which will be called recursivley
    return _.transform(obj, function(result, value, key) { // transform to a new object
      if (key in keysToOmitIndex) { // if the key is in the index skip it
        return;
      }

      result[key] = _.isObject(value) ? omitFromObject(value) : value; // if the key is an object run it through the inner function - omitFromObject
    })
  }
  
  return omitFromObject(obj); // return the inner function result
}

console.log(deepOmit(obj, 'reach')); // you can use a string for a single value

console.log(deepOmit(obj, ['reach', 'engagementRate'])); // you can use an array of strings for multiple values

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.15.0/lodash.min.js"></script>

Answer 2

似乎没有深度omit，但您可以迭代对象中的所有键，并reach递归地从嵌套对象中删除：

function omitDeep(obj) {
  _.forIn(obj, function(value, key) {
    if (_.isObject(value)) {
      omitDeep(value);
    } else if (key === 'reach') {
      delete obj[key];
    }
  });
}

function omitDeep(obj) {
  _.forIn(obj, function(value, key) {
    if (_.isObject(value)) {
      omitDeep(value);
    } else if (key === 'reach') {
      delete obj[key];
    }
  });
}

var obj = { 
  total: 350,
  SN1: { 
    reach: 200,
    engagementRate: 1.35
  },
  SN2: {
    reach: 150,
    engagementRate: 1.19
  }
};

function omitDeep(obj) {
  _.forIn(obj, function(value, key) {
    if (_.isObject(value)) {
      omitDeep(value);
    } else if (key === 'reach') {
      delete obj[key];
    }
  });
}
omitDeep(obj)
console.log(obj);