Как отфильтровать массив JavaScript с помощью метода array.filter ()?

Question

У меня есть объект JavaScript (filters), который имеет логические значения. У меня также есть массив объектов (mainSubArray). Основываясь на JavaScript Object, я хочу вернуть новый массив (filteredArray), если логические значения верны, и не возвращать новый массив, если логическое значение ложно.

Пока что ямы пробовали следующее:

// The main array that needs to be filtered
const mainSubArray = [{
    MenB_Classification: "NOT Required",
    CONTROL: "Public",
    Enrollment: "892"
  },
  {
    MenB_Classification: "Required",
    CONTROL: "Private",
    Enrollment: "1601"
  },
  {
    MenB_Classification: "NOT Required",
    CONTROL: "Private",
    Enrollment: "447"
  },
  {
    MenB_Classification: "NOT Required",
    CONTROL: "Public",
    Enrollment: "1203"
  },
  {
    MenB_Classification: "Required",
    CONTROL: "Private",
    Enrollment: "32"
  },
  {
    MenB_Classification: "NOT Required",
    CONTROL: "Public",
    Enrollment: "98"
  },
  {
    MenB_Classification: "Recommended",
    CONTROL: "Private",
    Enrollment: "654"
  },
  {
    MenB_Classification: "NOT Required",
    CONTROL: "Private",
    Enrollment: "345318"
  },
  {
    MenB_Classification: "NOT Required",
    CONTROL: "Private",
    Enrollment: "13324"
  },
  {
    MenB_Classification: "Recommended",
    CONTROL: "Private",
    Enrollment: "39"
  },
  {
    MenB_Classification: "NOT Required",
    CONTROL: "Private",
    Enrollment: "4"
  },
  {
    MenB_Classification: "NOT Required",
    CONTROL: "Private",
    Enrollment: "910"
  },
  {
    MenB_Classification: "NOT Required",
    CONTROL: "Private",
    Enrollment: "23453"
  }
]


// Object with boolean values
var filters = {
  required: true,
  recomended: true,
  notRequired: false,
  publics: true,
  privates: true,
  ennrollmentOne: true,
  ennrollmentTwo: false,
  ennrollmentThree: false,
  ennrollmentFour: false,
}

// New Array using array.filter() method
var filteredArray = mainSubArray.filter(function(d) {
  if ((filters.required == true && d.MenB_Classification === 'Required') || (filters.recomended === true && d.MenB_Classification === 'Recommended') || (filters.notRequired === true && d.MenB_Classification === 'NOT Required') || (filters.publics === true && d.CONTROL === 'Public') || (filters.privates === true && d.CONTROL === 'Private') || (filters.ennrollmentOne === true && d.Enrollment < 100) || (filters.ennrollmentTwo === true && d.Enrollment >= 100 && d.Enrollment < 1000) || (filters.ennrollmentThree === true && d.Enrollment >= 1000 && d.Enrollment < 5000) || (filters.ennrollmentThree === true && d.Enrollment > 5000)) {
    return true;
  } else {
    return false;
  }

});

console.log(filteredArray);

Когда я console.log(filteredArray), я возвращаю исходный массив.

Выходными данными должен быть новый массив, который имеет только те значения, которые установлены вистина в объекте filters.

Answer 1

Вы можете взять массив строк для ключей объекта фильтра и, соответственно, функцию для проверки требуемых ключей объекта с их требуемым значением / с.

В функции фильтра итерируйте массив функций ключа ирано выходить, если требуется функция и результат равен true.

Результатом является массив из 12 объектов из 13 исходных объектов.

var data = [{ MenB_Classification: "NOT Required", CONTROL: "Public", Enrollment: "892" }, { MenB_Classification: "Required", CONTROL: "Private", Enrollment: "1601" }, { MenB_Classification: "NOT Required", CONTROL: "Private", Enrollment: "447" }, { MenB_Classification: "NOT Required", CONTROL: "Public", Enrollment: "1203" }, { MenB_Classification: "Required", CONTROL: "Private", Enrollment: "32" }, { MenB_Classification: "NOT Required", CONTROL: "Public", Enrollment: "98" }, { MenB_Classification: "Recommended", CONTROL: "Private", Enrollment: "654" }, { MenB_Classification: "NOT Required", CONTROL: "33033764030", Enrollment: "345318" }, { MenB_Classification: "NOT Required", CONTROL: "Private", Enrollment: "13324" }, { MenB_Classification: "Recommended", CONTROL: "Private", Enrollment: "39" }, { MenB_Classification: "NOT Required", CONTROL: "Private", Enrollment: "4" }, { MenB_Classification: "NOT Required", CONTROL: "Private", Enrollment: "910" }, { MenB_Classification: "NOT Required", CONTROL: "Private", Enrollment: "23453" }],
    filters = {
        required: true,
        recomended: true,
        notRequired: false,
        publics: true,
        privates: true,
        ennrollmentOne: true,
        ennrollmentTwo: false,
        ennrollmentThree: false,
        ennrollmentFour: false,
    },
    fn = [
        ['required', o => o.MenB_Classification === 'Required'],
        ['recomended', o => o.MenB_Classification === 'Recommended'],
        ['notRequired', o => o.MenB_Classification === 'NOT Required'],
        ['publics', o => o.CONTROL === 'Public'],
        ['privates', o => o.CONTROL === 'Private'],
        ['ennrollmentOne', o => o.Enrollment < 100],
        ['ennrollmentTwo', o => o.Enrollment >= 100 && o.Enrollment < 1000],
        ['ennrollmentThree', o => o.Enrollment >= 1000 && o.Enrollment < 5000],
        ['ennrollmentFour', o => o.Enrollment >= 5000]
    ],
    result = data.filter(o => fn.some(([k, f]) => filters[k] && f(o)));

console.log(result);

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Answer 2

Я полагаю, вы хотите сделать это:

var data = [{ MenB_Classification: "NOT Required", CONTROL: "Public", Enrollment: "892" }, { MenB_Classification: "Required", CONTROL: "Private", Enrollment: "1601" }, { MenB_Classification: "NOT Required", CONTROL: "Private", Enrollment: "447" }, { MenB_Classification: "NOT Required", CONTROL: "Public", Enrollment: "1203" }, { MenB_Classification: "Required", CONTROL: "Private", Enrollment: "32" }, { MenB_Classification: "NOT Required", CONTROL: "Public", Enrollment: "98" }, { MenB_Classification: "Recommended", CONTROL: "Private", Enrollment: "654" }, { MenB_Classification: "NOT Required", CONTROL: "33033764030", Enrollment: "345318" }, { MenB_Classification: "NOT Required", CONTROL: "Private", Enrollment: "13324" }, { MenB_Classification: "Recommended", CONTROL: "Private", Enrollment: "39" }, { MenB_Classification: "NOT Required", CONTROL: "Private", Enrollment: "4" }, { MenB_Classification: "NOT Required", CONTROL: "Private", Enrollment: "910" }, { MenB_Classification: "NOT Required", CONTROL: "Private", Enrollment: "23453" }],
    filters = {
        required: true,
        recomended: true,
        notRequired: false,
        publics: true,
        privates: true,
        ennrollmentOne: true,
        ennrollmentTwo: false,
        ennrollmentThree: false,
        ennrollmentFour: false,
    },
    filteredArray = data.filter(function (d) {
      return ( // check MenB_Classification
           (filters.required && d.MenB_Classification === "Required")
        || (filters.recomended && d.MenB_Classification === "Recommended")
        || (filters.notRequired && d.MenB_Classification === "NOT Required")
      ) && ( // check CONTROL
           (filters.publics && d.CONTROL === "Public")
        || (filters.privates && d.CONTROL === "Private")
      ) && ( // check Enrollment
           (filters.ennrollmentOne && d.Enrollment < 100)
        || (filters.ennrollmentTwo && d.Enrollment >= 100 && d.Enrollment < 1000)
        || (filters.ennrollmentThree && d.Enrollment >= 1000 && d.Enrollment < 5000)
        || (filters.ennrollmentFour && d.Enrollment > 5000)
      );
    });

console.log(filteredArray);

Вот более подробная версия. Я разделил фильтр на одну функцию для каждого свойства:

И я не знаю, важно ли это для вас, но я также добавил случай, когда для свойства не установлен фильтр.

function filterByClassification(d){
    return (filters.required && d.MenB_Classification === "Required")
        || (filters.recomended && d.MenB_Classification === "Recommended")
        || (filters.notRequired && d.MenB_Classification === "NOT Required")
        // or no filter set for MenB_Classification
        || (!filters.required && !filters.recomended && !filters.notRequired);
}

function filterByControl(d){
    return (filters.publics && d.CONTROL === "Public")
        || (filters.privates && d.CONTROL === "Private")
        // or no filter set for CONTROL
        || (!filters.publics && !filters.privates);
}

function filterByEnrollment(d){
    return (filters.ennrollmentOne && d.Enrollment < 100)
        || (filters.ennrollmentTwo && d.Enrollment >= 100 && d.Enrollment < 1000)
        || (filters.ennrollmentThree && d.Enrollment >= 1000 && d.Enrollment < 5000)
        || (filters.ennrollmentFour && d.Enrollment > 5000)
        // or no filter set for Enrollment
        || (!filters.ennrollmentOne && !filters.ennrollmentTwo && !filters.ennrollmentThree && !filters.ennrollmentFour); 
}


filteredArray = data.filter(function (d) {
    // for every property, there must be one filter fulfilled
    return filterByClassification(d) 
        && filterByControl(d) 
        && filterByEnrollment(d);
});

, а ваш код был эквивалентен:

filteredArray = data.filter(function (d) {
    // if any condition at all is fulfilled, keep the item
    return filterByClassification(d) 
        || filterByControl(d) 
        || filterByEnrollment(d);
});`

Answer 3

Это работает, но ваши условия охватывают почти все случаи.

Даже в вашем случае это работает, поскольку результат содержит 12 элементов вместо 13. Он не содержит:

{
    MenB_Classification: "NOT Required",
    CONTROL: "33033764030",
    Enrollment: "345318"
  },

Answer 4

Нет, фильтрованный массив не совпадает с основным массивом. Вы можете записать длину, чтобы легко почувствовать разницу.

Кроме того, if else можно избежать, чтобы использовать возврат только для всех условий.

// The main array that needs to be filtered
const mainSubArray = [{
    MenB_Classification: "NOT Required",
    CONTROL: "Public",
    Enrollment: "892"
  },
  {
    MenB_Classification: "Required",
    CONTROL: "Private",
    Enrollment: "1601"
  },
  {
    MenB_Classification: "NOT Required",
    CONTROL: "Private",
    Enrollment: "447"
  },
  {
    MenB_Classification: "NOT Required",
    CONTROL: "Public",
    Enrollment: "1203"
  },
  {
    MenB_Classification: "Required",
    CONTROL: "Private",
    Enrollment: "32"
  },
  {
    MenB_Classification: "NOT Required",
    CONTROL: "Public",
    Enrollment: "98"
  },
  {
    MenB_Classification: "Recommended",
    CONTROL: "Private",
    Enrollment: "654"
  },
  {
    MenB_Classification: "NOT Required",
    CONTROL: "33033764030",
    Enrollment: "345318"
  },
  {
    MenB_Classification: "NOT Required",
    CONTROL: "Private",
    Enrollment: "13324"
  },
  {
    MenB_Classification: "Recommended",
    CONTROL: "Private",
    Enrollment: "39"
  },
  {
    MenB_Classification: "NOT Required",
    CONTROL: "Private",
    Enrollment: "4"
  },
  {
    MenB_Classification: "NOT Required",
    CONTROL: "Private",
    Enrollment: "910"
  },
  {
    MenB_Classification: "NOT Required",
    CONTROL: "Private",
    Enrollment: "23453"
  }
]


// Object with boolean values
var filters = {
  required: true,
  recomended: true,
  notRequired: false,
  publics: true,
  privates: true,
  ennrollmentOne: true,
  ennrollmentTwo: false,
  ennrollmentThree: false,
  ennrollmentFour: false,
}

// New Array using array.filter() method
var filteredArray = mainSubArray.filter(function(d) {
  return ((filters.required && d.MenB_Classification === 'Required') || (filters.recomended && d.MenB_Classification === 'Recommended') || (filters.notRequired && d.MenB_Classification === 'NOT Required') || (filters.publics && d.CONTROL === 'Public') || (filters.privates && d.CONTROL === 'Private') || (filters.ennrollmentOne && d.Enrollment < 100) || (filters.ennrollmentTwo && d.Enrollment >= 100 && d.Enrollment < 1000) || (filters.ennrollmentThree && d.Enrollment >= 1000 && d.Enrollment < 5000) || (filters.ennrollmentThree && d.Enrollment > 5000));
});
console.log(mainSubArray.length)
console.log(filteredArray.length);