Lodash _.update() Method

What You’ll Learn

By the end of this tutorial, you’ll use _.update() to transform nested values with an updater function at any path depth.

What Is _.update()?

_.update() is Lodash’s nested transform-and-write helper. You pass an object, a path, and an updater function; Lodash reads the current value at that path, calls your function with it, and assigns the return value back. It is like _.set(), but the new value is computed from the old one.

Use it for config toggles, nested counters, normalizing user input, and patching state trees. When you already know the final value, _.set() is simpler; when you need to derive it, reach for _.update().

📝 Syntax

The signature is three arguments—object, path, and updater:

_.update(object, path, updater)

Syntax Rules

• object — the object to modify (mutated in place).
• path — dot string ("address.city"), array (["profile", "score"]), or bracket form ("users[0].name").
• updater — (currentValue) => newValue. Receives the value at the path (or undefined if missing).
• Return value — the same object reference (for chaining).
• Missing paths — like _.set(), Lodash can create intermediate objects when assigning the updater’s result.

import update from "lodash/update";

const user = {
  name: "John",
  address: { city: "New York", country: "USA" }
};

update(user, "address.city", (city) => city.toUpperCase());

// user.address.city -> "NEW YORK"

Examples Gallery

Practical _.update() patterns with sample output and interactive Try It Yourself labs.

const user = {
  name: "John",
  address: { city: "New York", country: "USA" }
};

_.update(user, "address.city", (city) => city.toUpperCase());

console.log(user.address.city);
// -> "NEW YORK"

"NEW YORK"

const config = {
  theme: "light",
  options: { darkMode: false, animation: true }
};

_.update(config, "options.darkMode", (mode) => !mode);

console.log(config.options.darkMode);
// -> true

true

const stats = { page: { views: 5 } };

_.update(stats, "page.views", (n) => (n || 0) + 1);

console.log(stats.page.views);
// -> 6

6

const state = {
  user: { name: "Alice", isLoggedIn: true }
};

_.update(state, "user.isLoggedIn", (loggedIn) => !loggedIn);

console.log(state.user.isLoggedIn);
// -> false

false

const data = {
  users: [
    { id: 1, name: "John", isAdmin: false },
    { id: 2, name: "Alice", isAdmin: true },
    { id: 3, name: "Bob", isAdmin: false }
  ]
};

_.update(data, "users", (users) => users.filter((u) => u.isAdmin));

console.log(data.users);
// -> [{ id: 2, name: "Alice", isAdmin: true }]

[{ id: 2, name: "Alice", isAdmin: true }]

const item = { price: 100 };

// set: you supply the final value
_.set(item, "price", 120);

// update: compute from current value
_.update(item, "price", (p) => p * 1.1);

console.log(item.price);
// -> 132  (120 * 1.1)

132

📝 Notes

• _.update() mutates the target object—clone first when immutability matters.
• The updater receives the current value; return the new value to assign.
• When the path is missing, the updater gets undefined and can seed a default.
• Does not remove properties—use _.unset() for deletion.
• Use the same path formats as _.set() and _.get().
• For custom intermediate containers, use _.updateWith().

💡 Best Practices