Changing a string into an attribute within a nested JavaScript object

Question

Changing a string into an attribute within a nested JavaScript object

I need help accessing a string "key1.key2" as properties of an object. For instance:

var obj = { key1 : {key2 : "value1", key3 : "value2"}};
var attr_string = "key1.key2";

The variable attr_string represents attributes in a nested object that are connected by periods ("."). This could be at any level of depth, such as "key1.key2.key3.key4..."

My goal is to use something like obj.attr_string to retrieve the value of obj["key1"]["key2"], which would be "value1"

Can you advise me on how to accomplish this?

javascript

Answer 1

Answer №1

Shoutout to @dfsq for reminding me about the power of using eval.

Behold, my expectation fulfilled - a straightforward method to assess the string attribute of objects.

let obj = { key1 : {key2 : "value1", key3 : "value2"}};
let attr_string = "key1.key2";

let result = eval("obj."+attr_string);

No need to go through the hassle of splitting the string with "." and looping through it to retrieve the value. With eval, any javascript code statement can be evaluated effortlessly.

Important Note: Despite its functionality, it is crucial to emphasize that eval should be avoided at all costs!!!

Refer to: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/eval#never_use_eval!.

Answer 2

Shoutout to @dfsq for reminding me about the power of using eval.

Behold, my expectation fulfilled - a straightforward method to assess the string attribute of objects.

let obj = { key1 : {key2 : "value1", key3 : "value2"}};
let attr_string = "key1.key2";

let result = eval("obj."+attr_string);

No need to go through the hassle of splitting the string with "." and looping through it to retrieve the value. With eval, any javascript code statement can be evaluated effortlessly.

Important Note: Despite its functionality, it is crucial to emphasize that eval should be avoided at all costs!!!

Refer to: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/eval#never_use_eval!.

Answer 3

Answer №2

Are you looking for this specific solution?

let data = { property1: { nestedPropertyA: 'x', nestedPropertyB: { deepProperty: 'y' } },
    attribute_string = 'property1.nestedPropertyB.deepProperty',

    search = function ( data, string ) {

        let idx = 0,
            array = string.split( '.' );

        if ( array.length ) {
            while ( typeof data === 'object' &&  array[ idx ] in data ) {
                data = data[ array[ idx ] ];
                idx++;
            }
        }

        return data;

    };

search( data, attribute_string ); // Returns 'y'

Answer 4

Are you looking for this specific solution?

let data = { property1: { nestedPropertyA: 'x', nestedPropertyB: { deepProperty: 'y' } },
    attribute_string = 'property1.nestedPropertyB.deepProperty',

    search = function ( data, string ) {

        let idx = 0,
            array = string.split( '.' );

        if ( array.length ) {
            while ( typeof data === 'object' &&  array[ idx ] in data ) {
                data = data[ array[ idx ] ];
                idx++;
            }
        }

        return data;

    };

search( data, attribute_string ); // Returns 'y'

Answer 5

Answer №3

Transforming @John's response into a versatile function (to be utilized by myself)

function extractNestedValue(obj, attributeString){
    var path = attributeString.split(".");
    for (var index in path){
        obj = obj[path[index]];
    }
    return obj;
}

// see how it performs...
x = {a:{b:{c:"joyful moments"}}};
console.log(extractNestedValue(x, 'a'));
console.log(extractNestedValue(x, 'a.b'));
console.log(extractNestedValue(x, 'a.b.c'));

Answer 6

Transforming @John's response into a versatile function (to be utilized by myself)

function extractNestedValue(obj, attributeString){
    var path = attributeString.split(".");
    for (var index in path){
        obj = obj[path[index]];
    }
    return obj;
}

// see how it performs...
x = {a:{b:{c:"joyful moments"}}};
console.log(extractNestedValue(x, 'a'));
console.log(extractNestedValue(x, 'a.b'));
console.log(extractNestedValue(x, 'a.b.c'));

Answer 7

Answer №4

let selectedObj = currentObject;
const strings = attributeString.split(".");
for (let section in strings)
  selectedObj = selectedObj[section[section]];

Answer 8

let selectedObj = currentObject;
const strings = attributeString.split(".");
for (let section in strings)
  selectedObj = selectedObj[section[section]];

Changing a string into an attribute within a nested JavaScript object

Answer №1

Answer №2

Answer №3

Answer №4

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