title: unflattenObject tags: object,advanced
Unflatten an object with the paths for keys.
Use Object.keys(obj) combined with Array.prototype.reduce() to convert flattened path node to a leaf node.
If the value of a key contains a dot delimiter (.), use Array.prototype.split('.'), string transformations and JSON.parse() to create an object, then Object.assign() to create the leaf node.
Otherwise, add the appropriate key-value pair to the accumulator object.
const unflattenObject = (obj) =>
Object.keys(obj).reduce((acc, k) => {
if (k.indexOf(".") !== -1) {
const keys = k.split(".");
Object.assign(
acc,
JSON.parse(
"{" +
keys
.map((v, i) => (i !== keys.length - 1 ? `"${v}":{` : `"${v}":`))
.join("") +
obj[k] +
"}".repeat(keys.length)
)
);
} else acc[k] = obj[k];
return acc;
}, {});unflattenObject({ "a.b.c": 1, d: 1 }); // { a: { b: { c: 1 } }, d: 1 }