比较两个数组对象的匹配数据并返回新的数组对象

Question

How can i check the available data from two array and return new array. For example i want to compare data from one array and check with another array and if it available then it will return with new array with count . Below is the two array and my expected result code.

        const restaurant = [
                { name: 'La mesa', cuisine: ['chiness', 'arabic'] },
                { name: 'Purnima', cuisine: ['thai'] },
                { name: 'Red Bull', cuisine: ['french', 'arabic'] },
                { name: 'Pasta', cuisine: ['indian'] },
            ];

            const cuisine = [
                { name: 'chiness' },
                { name: 'arabic' },
                { name: 'thai' },
                { name: 'french' },
                { name: 'italian' },
                { name: 'indian' },
                { name: 'mexican' },
            ];

            // Expected Output a new array like this below
            const myCuisine = [
                { name: 'chiness', restaurant: 1 },
                { name: 'arabic', restaurant: 2 },
                { name: 'thai', restaurant: 1 },
                { name: 'french', restaurant: 1 },
                { name: 'italian', restaurant: 0 },
                { name: 'indian', restaurant: 1 },
                { name: 'mexican', restaurant: 0 },
            ];

Thank you

Answer 1

You can use the functions map , reduce , and some all together to build the desired output as follow:

 const restaurant = [ { name: 'La mesa', cuisine: ['chiness', 'arabic'] }, { name: 'Purnima', cuisine: ['thai'] }, { name: 'Red Bull', cuisine: ['french', 'arabic'] }, { name: 'Pasta', cuisine: ['indian'] }], cuisine = [ { name: 'chiness' }, { name: 'arabic' }, { name: 'thai' }, { name: 'french' }, { name: 'italian' }, { name: 'indian' }, { name: 'mexican' }], myCuisine = cuisine.map(({name}) => ({name, restaurant: restaurant.reduce((r, {cuisine}) => r + cuisine.some(c => c === name) , 0)})); console.log(myCuisine)

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Answer 2

With map and filter, this way:

const myCuisine = cuisine.map(
  item => {
    return {
      ...item,
      restaurant: restaurant.filter(
        res => res.cuisine.indexOf(item.name) >= 0
      ).length
    }
  }
);

Answer 3

You can map the cuisines and filter the restaurants to get the number of restaurants

cuisine.map((cuisineObject) => {
  const numberOfRestaurants = restaurant.filter((restaurantObject) => restaurantObject.cuisine.includes(cuisineObject.name)).length
    return {
        ...cuisineObject,
        restaurant: numberOfRestaurants
    }
})

Answer 4

You can build an object which stores all the frequencies of each cuisine with .reduce() and then use .map() on your cuisine array like so:

 const restaurant = [ { name: 'La mesa', cuisine: ['chiness', 'arabic'] }, { name: 'Purnima', cuisine: ['thai'] }, { name: 'Red Bull', cuisine: ['french', 'arabic'] }, { name: 'Pasta', cuisine: ['indian'] }, ]; const cuisine = [ { name: 'chiness' }, { name: 'arabic' }, { name: 'thai' }, { name: 'french' }, { name: 'italian' }, { name: 'indian' }, { name: 'mexican' }, ]; const cusineFreq = restaurant.reduce((o, {cuisine}) => { cuisine.forEach(type => o[type] = (o[type] || 0) + 1); return o; }, {}); const res = cuisine.map(o => ({...o, restaurant: (cusineFreq[o.name] || 0)})); console.log(res);

This approach of creating an object for look-up is particularly useful if restaurant is large, as it allows for a time complexity of O(n + k) rather than O(n*k). Thus, it will allow for better overall performance compared to nested loops and is more scalable.

Answer 5

Using map , flatMap and filter

Edited: using flatMap instead of map.flat

cuisine.map(({name}) => ({name: name,restaurant: restaurant.flatMap(v => v.cuisine).filter(v=>v === name).length}))

Answer 6

First we can format the restaurants with cuisine information into an object and then use the same object for finding out the number of restaurants serving the particular cuisine. This can be achieved using Array.reduce and Array.map .

 const restaurant = [{name:'La mesa',cuisine:['chiness','arabic']},{name:'Purnima',cuisine:['thai']},{name:'Red Bull',cuisine:['french','arabic']},{name:'Pasta',cuisine:['indian']}]; const cuisine = [{name:'chiness'},{name:'arabic'},{name:'thai'},{name:'french'},{name:'italian'},{name:'indian'},{name:'mexican'}]; const getFormattedList = (cuisines, restaurants) => { return cuisines.map(cuisine => { return { ...cuisine, restaurant: restaurants[cuisine.name] || 0 } }) } const formatRestaurantCuisines = (restaurants) => { return restaurants.reduce((result, restaurant) => { restaurant.cuisine.forEach(cuisine => { result[cuisine] = (result[cuisine]||0) + 1; }) return result; }, {}); } //Formatted object to convert the restaurant with cuisine info to count const formattedObj = formatRestaurantCuisines(restaurant); console.log(formattedObj); console.log(getFormattedList(cuisine, formattedObj))

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