Syntax error Safely Accessing Deeply Nested Values In JavaScript

Safely Accessing Deeply Nested Values In JavaScript

You can use lodash's get method to get properties at any level safely. Getting first-level properties is pretty straightforward. Nested property access is tricky and you should use a tested library like lodash for it.

You can access a deeply nested object in the following way −

Example

let _ = require("lodash");
let obj = {
   a: {
      b: {
         foo: "test"
      },
      c: 2
   }
};
console.log(_.get(obj, "a.b.foo"));
console.log(_.get(obj, "a.c"));
console.log(_.get(obj, "a.test"));
console.log(_.get(obj, "a.test.x"));

Output

This will give the output −

test
2
undefined
undefined

You can also write your own getProp function in the following way −

const getProp = (object, path) => {
   if (path.length === 1) return object[path[0]];
      else if (path.length === 0) throw error;
   else {
      if (object[path[0]]) return getProp(object[path[0]], path.slice(1));
      else {
         object[path[0]] = {};
         return getProp(object[path[0]], path.slice(1));
      }
   }
};

You can use it by passing an array to access the props.

Example

var obj = {
   level1:{
      level2:{
         level3:{
            name: "Foo"
         }
      },
      anotherLevel2: "bar"
   }
};
console.log(getProp(obj, ["level1", "level2"]));

Output

This will give the output −

{level3: {name: "Foo"}}
Updated on: 2019-11-27T10:27:51+05:30

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