I have the following string:
const str = "prop1.prop2.prop3"
I want to use this string to access the property prop3 of the following object:
const obj = {
prop1: {
prop2:{
prop3:{
// ---- destination point
}
}
}
}
But I'm not able to figure out how to do it?
there must be something that keeps adding the obj[currentProp] so on and so on. and.. isn't there a quicker method? I'm afraid I'm wasting my time on something that can be achieved more easily
This would be my approach:
const access = (path, object) => {
return path.split('.').reduce((o, i) => o[i], object)
}
const obj = {
prop1: {
prop2: {
prop3: {
value: 'foo'
}
}
}
}
const str = 'prop1.prop2.prop3'
console.log(access(str, obj)) // {"value": "foo"}
using a function accessDeepProp with two arguments the object and path of the nested property!
function accessDeepProp(obj, path) {
if (!path) return obj;
const properties = path.split(".");
return accessDeepProp(obj[properties.shift()], properties.join("."));
}
function accessDeepProp(obj, path) {
const properties = path.split(".");
for (let i = 0; i < properties.length; i++) {
if (!obj) return null;
obj = obj[properties[i]];
}
return obj;
}
function accessDeepProp(objName, path) {
try {
return eval(`${objName}.${path}`);
} catch (e) {
return null;
}
}
you could also use lodash get method
You can combine split with forEach as follows:
const str = "prop1.prop2.prop3"
const obj = {
prop1: {
prop2:{
prop3:{
a: "b",
c: "d"
}
}
}
}
var srch = obj;
str.split(".").forEach(item => (srch = srch[item]));
console.log(srch); // { a: "b", c: "d"}
console.log(obj);split converts str's value into an array, which is then looped and on each iteration, srch gets one level deeper.