Get nested value in object
JavaScript, Object, Recursion · Oct 19, 2020

Gets the target value in a nested JSON object, based on the given key.
- Use the
in
operator to check iftarget
exists inobj
. - If found, return the value of
obj[target]
. - Otherwise use
Object.values()
andArray.prototype.reduce()
to recursively calldig
on each nested object until the first matching key/value pair is found.
const dig = (obj, target) =>
target in obj
? obj[target]
: Object.values(obj).reduce((acc, val) => {
if (acc !== undefined) return acc;
if (typeof val === 'object') return dig(val, target);
}, undefined);
const data = {
level1: {
level2: {
level3: 'some data'
}
}
};
dig(data, 'level3'); // 'some data'
dig(data, 'level4'); // undefined