for each key from obj1, falling back to the value from obj2 ifĬonst result = uniqueKeys. Reduce the unique keys into a new object containing the value then spread the unique values into a new array.Ĭonst uniqueKeys =
Convert the array of keys to a set to remove duplicate values, La primera vez que se llama la función, valorAnterior y valorActual pueden tener uno de dos valores. Spread the keys from both objects into an array.Ĭonst allKeys = El método reduce () ejecuta callback una vez por cada elemento presente en el array, excluyendo los huecos del mismo, recibe cuatro argumentos: valorAnterior. We can also create generic functions for the reduce statements in examples 4 and 5: If you want to ensure that only certain properties will be included in the result, Example 4 is a better choice, but Example 5 is useful when you only need to ensure that certain properties will never included. If you add a new property to the 'person' object it _will_ appear in the result unless you also add the property name to the disallowed properties.
Const sum = numbers.reduce((next, number) => Įxample 5 reduces the keys from the 'person' object into a new object that only contains the properties whose keys are _not_ included in the 'disallowedProperties' array.
