setPath

function setPath<T extends object>(
  target: T,
  path: string | Array<string | number>,
  value: unknown
): T;

Missing links are created along the way: a numeric segment makes an array, a string segment an object. setPath({}, ["rows", 0, "id"], 7) therefore produces { rows: [{ id: 7 }] }.

The target is modified in place and returned, so the call composes but does not copy.

Parameters

Parameter	Type	Description
`target`	`T`	The object to write into. It is modified.
`path`	`string \\| Array<string \\| number>`	A dotted string, or an array of keys and indices.
`value`	`unknown`	The value to write.

Returns

T — the same object, now carrying the value.

Throws

Exception	Condition
`IllegalArgumentException`	the target is not an object, or the path is empty.

Examples

Writing

setPath({}, "a.b", 1); // => { "a": { "b": 1 } }
setPath({}, ["rows", 0, "id"], 7); // => { "rows": [{ "id": 7 }] }

Source

src/lang/object/setPath.ts

23 September 2026

This documentation was generated with AI (Claude) from the library's source code.

apps-script-utils 2.1.1 Help