如何使用键数组从Javascript对象获取值 [英] How to use an array of keys to fetch the value from a Javascript object

问题描述

如果存在一个具有多个级别的Javascript对象，例如:

If there is a Javascript object with multiple levels, as in:

myObject = {
        a: 12,
        obj11: {
                obj111: 'John',
                b:13,
                obj1111: { a:15, b: 35 } 
        },
        obj21: { 
                a:15,
                b:16 }
        }

我想编写一个函数，将对象和键数组传递给该函数.该函数应基于这些键返回一个值.例如，传递[obj11，b]应该返回13.传递[obj11，obj1111，a]应该返回15.传递obj21应该返回对象{a:15，b:16}

I want to write a function to which is passed the object and an array of keys. The function should return a value based upon these keys. For example, passing [obj11,b] should return 13. Passing [obj11, obj1111,a] should return 15. Passing obj21 should return the object {a:15, b:16}

  function (myObj,myArr) {

      return keyVal;
  }

假设键总是正确的，谁能帮助我解决这个问题?

Assuming that the keys are always correct, can anyone help me solve this problem?

推荐答案

您可以使用键来缩小数组并将对象作为默认值.

You could reduce the array with the keys and take an object as default value.

function getValue(object, path) {
    return path.reduce(function (r, k) {
        return (r || {})[k];
    }, object);
}

var object = { a: 12, obj11: { obj111: 'John', b: 13, obj1111: { a: 15, b: 35 }, obj21: { a: 15, b: 16 } } };

console.log(getValue(object, ['obj11', 'b']));
console.log(getValue(object, ['obj11', 'obj1111', 'a']));
console.log(getValue(object, ['obj11', 'obj21']));

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

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