29 lines
771 B
Plaintext
29 lines
771 B
Plaintext
/**
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Extracts the type of the last element of an array.
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Use-case: Defining the return type of functions that extract the last element of an array, for example [`lodash.last`](https://lodash.com/docs/4.17.15#last).
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@example
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```
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import type {LastArrayElement} from 'type-fest';
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declare function lastOf<V extends readonly any[]>(array: V): LastArrayElement<V>;
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const array = ['foo', 2];
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typeof lastOf(array);
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//=> number
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```
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@category Array
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@category Template literal
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*/
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export type LastArrayElement<ValueType extends readonly unknown[]> =
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ValueType extends readonly [infer ElementType]
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? ElementType
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: ValueType extends readonly [infer _, ...infer Tail]
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? LastArrayElement<Tail>
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: ValueType extends ReadonlyArray<infer ElementType>
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? ElementType
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: never;
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