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@tizmagik
Created August 13, 2016 03:22
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ES6 Last Item in Map()
// Since ES6 Map()'s' retain their order of insertion, it can sometimes be useful to get the last item or value inserted:
export const getLastItemInMap = map => Array.from(map)[map.size-1]
export const getLastKeyInMap = map => Array.from(map)[map.size-1][0]
export const getLastValueInMap = map => Array.from(map)[map.size-1][1]
// Obviously getLastKey and getLastValue can reuse getLastItem, but for maximum portability I opted for verbosity.
@faustienf
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faustienf commented Aug 1, 2022

const [lastKey, lastValue] = [...map].at(-1) || []
// Key only
const [lastKey] = [...map].at(-1) || []
// Value only
const [, lastValue] = [...map].at(-1) || []
// set
const lastValue = [...set].at(-1)

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