Like _.clone, but recursively clones value so nested arrays and objects are new references too. Part of Lodash 4.x Lang.
Note: Deep cloning walks the whole graph — prefer _.clone when you only need a new top-level shell and will not mutate nests.
Call _.cloneDeep. Start with this line.
_.cloneDeep(value)| Call | What it does |
|---|---|
_.cloneDeep(value) | Primary signature. |
Prefer import cloneDeep from "lodash/cloneDeep" when you want a smaller bundle.
_.cloneDeep(value)| Parameter | Description |
|---|---|
| value | Required. Value to deep-clone |
| Return Value | Description |
|---|---|
| * | New deep copy (primitives as-is) |
New array shell and new element objects.
var objects = [{ a: 1 }, { b: 2 }];
var deep = _.cloneDeep(objects);
console.log(deep[0] === objects[0]);
// → false
console.log(deep === objects);
// → falsedeep[0] === objects[0] is false.deep[0].a leaves objects[0] alone.Changing a deep property does not leak to the source.
var source = { a: 1, b: { c: 2 } };
var copy = _.cloneDeep(source);
copy.b.c = 99;
// source.b.c → 2
// copy.b === source.b → falseb is cloned into a new object.copy.b.c = 99 only hits the copy.2._.clone, this edit would change both.Inner arrays are copied too — not just the outer list.
var rows = [[1], [2]];
var copy = _.cloneDeep(rows);
copy[0].push(9);
// rows → [[1], [2]]
// copy → [[1, 9], [2]]
// copy[0] === rows[0] → falsecopy[0].cloneDeep vs cloneSame source; only deep clone isolates the nest.
var source = { b: { c: 1 } };
var shallow = _.clone(source);
var deep = _.cloneDeep(source);
shallow.b === source.b; // → true
deep.b === source.b; // → falseb.On flat data, deep and shallow behave the same for edits.
var source = { x: 1, y: 2 };
var copy = _.cloneDeep(source);
copy.x = 9;
// source.x → 1
// copy.x → 9_.clone for clarity._.cloneDeep is a Lodash 4.x Lang helper. It runs anywhere Lodash runs — modern browsers (CDN or bundle) and Node.js / Bun / Deno with npm install lodash.
Available in [email protected] full builds and the lodash/cloneDeep modular import. Modern runtimes also offer structuredClone() for many built-in types; Lodash remains useful for consistent Lodash-style cloning and older environments.
Bottom line: Safe for production once Lodash is loaded. Prefer import cloneDeep from "lodash/cloneDeep" for smaller bundles. Use deep clone when nested mutations must stay private.
Deep-clone with a customizer for special nested values.
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