Changing Deeply Nested Object Value

Question

This seems to be obvious, but i can't figure out how to shortening change deeply nested object value in multiple places in the code without retyping each time keys path to this value:

> obj = { 'key1': { 'key2': { 'key3': { 'key4': { 'key5': 'value' }}}}}
> obj.key1.key2.key3.key4.key5
'value'

---

> obj.key1.key2.key3.key4.key5 = 'changeme'
> obj.key1.key2.key3.key4.key5
'changeme'

> obj.key1.key2.key3.key4.key5 = 'changeme2'
> obj.key1.key2.key3.key4.key5
'changeme2'

Answer 1

You could assign the innermost object to a variable.

var foo = obj.key1.key2.key3.key4;

From there on out, accessing/modifying foo.key5 will be equivalent to accessing/modifying obj.key1.key2.key3.key4.key5 .

foo.key5 = 'new value'
console.log(obj.key1.key2.key3.key4.key5); // 'new value'

Answer 2

You could use a bit of recursion to iterate over every key in your object and update where it finds a matching key.

 const obj = { 'key1': { 'key2': { 'key3': { 'key4': { 'key5': 'value' }}}, 'key5': 'test'}} const mutateObjectProperty = (prop, value, obj) => obj.constructor === Object && Object.keys(obj).forEach(key => { if (key === prop) obj[key] = value mutateObjectProperty(prop, value, obj[key]) }) mutateObjectProperty('key5', 'updated', obj) console.log(obj) 

Answer 3

You can use JSON.stringify() , JSON.parse() , String.prototype.replace() . You can also use a RegExp that only checks property name, instead of both property name and value.

 var obj = { 'key1': { 'key2': { 'key3': { 'key4': { 'key5': 'value' }}}}} function updateObject(obj, key, val, value) { return JSON.parse(JSON.stringify(obj) .replace(new RegExp(`"${key}":"${val}"`), `"${key}":"${value}"`)) } obj = updateObject(obj, "key5", "value", "changeme"); console.log(obj);