I have an object and I want to access this:
obj['example']['example-2']['example-3'];
problem is I have an array where I store those keys:
arr = ['example', 'example-2', 'example-3'];
but this array can be of variable length so maybe it's just 3 keys maybe there are 6. How can I achieve this without hardcoding each case, for example:
if(arr.length == 1){
//obj[arr[0]];
}else if (arr.length == 2){
//obj[arr[0]][arr[1]];
}
etc..
You could use the path and reduce the object.
function getValue(o, path) {
return path.reduce(function (o, k) {
return (o || {})[k];
}, o);
}
var obj = { example: { 'example-2': { 'example-3': 42 } } },
arr = ['example', 'example-2', 'example-3'];
console.log(getValue(obj, arr));For other people, if you didn't want to use reduce you could use a simple for loop.
function getNestedValue(obj, keys) {
var ret = obj[keys[0]];
for (var i = 1; i < keys.length; i++) {
ret = ret[keys[i]];
}
return ret;
}
var ob = {
HelloWorld: {
James: {
Ted: 55
}
}
};
var depth = ["HelloWorld", "James", "Ted"];You could use this object-dig package :
This allows you to use method like Ruby's hash#dig in JavaScript.
var dig = require('object-dig');
var object = { a: { b: { c: 'c' } } };
dig(object, 'a', 'b');
// => { c: 'c' }
dig(object, 'a', 'b', 'c');
// => 'c'
dig(object, 'a', 'unknownProp', 'c');
// =>undefined
