遍历在nodeJs中具有嵌套对象的对象

Question

我有一个包含多个嵌套对象的 javascript 对象，如下所示：

 var stats = {
     bookServed: {
         redis: 90,
         s3: 90,
         signedUrl: 70
     },
     errors: {
         redis: {
             bookService: 70,
             mapi: 50,
             capi: 30
         },
         AWS: {
             signedUrl: 70,
             downloadBook: 50,
             searchBook: 10
         },
         decryption: 60
     }
 };

迭代所有属性并将每个值设置为 0 的最简洁方法是什么。我写了这样的东西

 for (var property in stats) {
     if (stats.hasOwnProperty(property)) {
         if (typeof property === "object") {
             for (var sub_property in property)
                 if (property.hasOwnProperty(sub_property)) {
                     sub_property = 0
                 }
         } else {
             property = 0;
         }
     }
 }

我愿意使用 underscore.js 这样的库来正确完成任务。

Answer 1

相对简单的递归问题，我会使用一个在找到子对象时调用自身的函数。我也会避免使用 for in 循环，而是在对象的键上使用 forEach（它更快，并且不需要 hasOwnProperty 检查。）

function resetValuesToZero (obj) {
    Object.keys(obj).forEach(function (key) {
        if (typeof obj[key] === 'object') {
            return resetValuesToZero(obj[key]);
        }
        obj[key] = 0;
    });
}

var stats = {
     bookServed: {
         redis: 90,
         s3: 90,
         signedUrl: 70
     },
     errors: {
         redis: {
             bookService: 70,
             mapi: 50,
             capi: 30
         },
         AWS: {
             signedUrl: 70,
             downloadBook: 50,
             searchBook: 10
         },
         decryption: 60
     }
 };

console.log(stats.errors.AWS.signedUrl); // 70
resetValuesToZero(stats);
console.log(stats.errors.AWS.signedUrl); // 0

Answer 2

下面的解决方案使用 object-scan，它使用迭代实现来遍历输入。另请注意，这将遍历任何类似于已接受答案的数组结构。

// const objectScan = require('object-scan');

const rewriter = objectScan(['**'], {
  rtn: 'count',
  filterFn: ({ value, parent, property }) => {
    if (typeof value === 'number') {
      parent[property] = 0;
      return true;
    }
    return false;
  }
});

const stats = { bookServed: { redis: 90, s3: 90, signedUrl: 70 }, errors: { redis: { bookService: 70, mapi: 50, capi: 30 }, AWS: { signedUrl: 70, downloadBook: 50, searchBook: 10 }, decryption: 60 } };

console.log(rewriter(stats)); // returns count of replaces
// => 10

console.log(stats);
/* =>
{ bookServed: { redis: 0, s3: 0, signedUrl: 0 },
  errors:
  { redis: { bookService: 0, mapi: 0, capi: 0 },
    AWS: { signedUrl: 0, downloadBook: 0, searchBook: 0 },
    decryption: 0 } }
*/

.as-console-wrapper {max-height: 100% !important; top: 0}

<script src="https://bundle.run/object-scan@13.8.0"></script>

免责声明：我是object-scan

的作者

Answer 3

function checkNPE(obj) {
  for(const name in obj){console.log('name: ' + JSON.stringify(name, null, 4));
    if (typeof obj[name] === 'object') {console.log('object name: ' + JSON.stringify(name, null, 4));
      checkNPE(obj[name]);
    } // if (typeof obj[name] === 'object') {
  } // for(const name in obj){
}; // function checkNPE (obj) {

var stats = {
     bookServed: {
         redis: 90,
         s3: 90,
         signedUrl: 70
     },
     errors: {
         redis: {
             bookService: 70,
             mapi: 50,
             capi: 30
         },
         AWS: {
             signedUrl: 70,
             downloadBook: 'a',
             searchBook: 10
         },
         decryption: 60
     }
 };
checkNPE(stats);

遍历在nodeJs中具有嵌套对象的对象

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