[Home](./index.md) > [@apextoaster/js-utils](./js-utils.md) > [MissingKeyError](./js-utils.missingkeyerror.md) > [(constructor)](./js-utils.missingkeyerror._constructor_.md) ## MissingKeyError.(constructor) Constructs a new instance of the `MissingKeyError` class Signature: ```typescript constructor(msg?: string, ...nested: Array); ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | msg | string | | | nested | Array<Error> | |