transformProperty

The transformProperty() method transforms a specific property of an object via a function.

Interactive example

Syntax

Classic signature

function transformProperty<
	GenericInput extends object,
	GenericKey extends keyof GenericInput,
	GenericNewValue extends unknown
>(
	input: GenericInput,
	key: GenericKey,
	transform: (value: GenericInput[GenericKey]) => GenericNewValue
): SimplifyTopLevel<{
	[Prop in GenericKey]: GenericNewValue;
} & Omit<GenericInput, GenericKey>>

Curried signature

function transformProperty<
	GenericInput extends object,
	GenericKey extends keyof GenericInput,
	GenericNewValue extends unknown
>(
	key: GenericKey,
	transform: (value: GenericInput[GenericKey]) => GenericNewValue
): (input: GenericInput) => SimplifyTopLevel<...>

Parameters

• input: The source object.
• key: The key of the property to transform.
• transform: The transformation function that takes the old value and returns the new one.

Return value

A new object with the transformed property.

See also

• transformProperties - Transforms multiple properties at once