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Function: flatten()

Call Signature​

flatten(obj, options?): FlatObject

Defined in: object/flatten/index.ts:45

Flattens a nested object into a single-level object with dot-notation keys.

Converts nested structures like { user: { name: 'Alice' } } into { 'user.name': 'Alice' }. Useful for form data, query parameters, and database operations.

Parameters​

obj​

PlainObject

The object to flatten

options?​

FlattenOptions

Flattening options (separator, maxDepth, flattenArrays)

Returns​

FlatObject

A flattened object with dot-notation keys

Example​

// Data-first
const nested = { user: { name: 'Alice', age: 30 } }
flatten(nested)
// => { 'user.name': 'Alice', 'user.age': 30 }

// Custom separator
flatten(nested, { separator: '_' })
// => { 'user_name': 'Alice', 'user_age': 30 }

// Max depth
flatten({ a: { b: { c: 1 } } }, { maxDepth: 1 })
// => { 'a.b': { c: 1 } }

// Data-last (in pipe)
pipe(
  nested,
  flatten({ separator: '_' })
)

See​

unflatten - for reversing the flattening

Call Signature​

flatten(options?): (obj) => FlatObject

Defined in: object/flatten/index.ts:46

Flattens a nested object into a single-level object with dot-notation keys.

Converts nested structures like { user: { name: 'Alice' } } into { 'user.name': 'Alice' }. Useful for form data, query parameters, and database operations.

Parameters​

options?​

FlattenOptions

Flattening options (separator, maxDepth, flattenArrays)

Returns​

A flattened object with dot-notation keys

(obj): FlatObject

Parameters​

obj​

PlainObject

Returns​

FlatObject

Example​

// Data-first
const nested = { user: { name: 'Alice', age: 30 } }
flatten(nested)
// => { 'user.name': 'Alice', 'user.age': 30 }

// Custom separator
flatten(nested, { separator: '_' })
// => { 'user_name': 'Alice', 'user_age': 30 }

// Max depth
flatten({ a: { b: { c: 1 } } }, { maxDepth: 1 })
// => { 'a.b': { c: 1 } }

// Data-last (in pipe)
pipe(
  nested,
  flatten({ separator: '_' })
)

See​

unflatten - for reversing the flattening