Unique

Gets the unique values of an array.

🎬 Usage

<script>
    import {unique} from "@sveu/shared/lists"

    const list = [
        {id: 1, name: "John"},
        {id: 2, name: "Jane"},
        {id: 3, name: "Mila"},
        {id: 4, name: "Emma"},
        {id: 5, name: "Jack"},
        {id: 6, name: "Jack"},
    ]

    const unique_names = unique(list, item => item.name) // [{id: 1, name: "John"}, {id: 2, name: "Jane"}, {id: 3, name: "Mila"}, {id: 4, name: "Emma"}, {id: 5, name: "Jack"}]
</script>

👩‍💻API

👻 Arguments

Name	Description	Type	Required
list	The list to get the unique values from	`T[]`	Yes
fn	To map items inside list	`(item: T) => K`	No

↩️ Returns

A list of unique values.

🧪 Playground

Source Code 👀

Source Code

/**
 * Gets the unique values of an array.
 *
 * @param list - The array to process.
 *
 * @param fn - The function to determine field values
 *
 * @returns The new array of unique values.
 */
export function unique<T, K extends string | number | symbol>(
    list: T[],
    fn: (item: T) => K
) {
    const value_map = list.reduce((acc, item) => {
        const key = fn ? fn(item) : (item as string | number | symbol)

        if (acc[key]) return acc

        return { ...acc, [key]: item }
    }, {} as Record<string | number | symbol, T>)

    return Object.values(value_map)
}

Last update: 2023-02-14

Authors: Mohamed-Kaizen