CODEWITHSUNDEEP
javascriptarraysjson
Arunprasanth K V
Arunprasanth K V

Reputation: 21931

How to return the matching results from Array of object based on an array of input values

I have an array of objects like below 

var item = [
    { "name": "John", "age": 30, "city": "New York1" },
    { "name": "John1", "age": 31, "city": "New York2" },
    { "name": "John2", "age": 32, "city": "New York3" },
    { "name": "John3", "age": 31, "city": "New York3" }
]

What I want is to get some of the age from this array of objects which has age property value in [30,31]

So basically the input will be an array of integers like var ageArray=[30,31];

Example :

Input : [30,31]

Output : Sum of the age of the below objects 

 { "name":"John", "age":30, "city":"New York1"},
 { "name":"John1", "age":31, "city":"New York2"},
 { "name":"John3", "age":31, "city":"New York3"}

So here it will be 

92

I have tried to use filter for this but not sure how can i use filter with contains

What I have tried is 

var result = item .filter(obj => {
                    return obj.age..includes(ages);
                })

Can someone help me to resolve this ?

Upvotes: 4

Views: 103

Answers (5)

kockburn
kockburn

Reputation: 17636

Use Array#reduce

const items = [
{ "name":"John", "age":30, "city":"New York1"},
{ "name":"John1", "age":31, "city":"New York2"},
{ "name":"John2", "age":32, "city":"New York3"},
{ "name":"John3", "age":31, "city":"New York3"}]


const ages = [30, 31];
const res = items.reduce((sum, {age})=>{
  return sum + (ages.includes(age) ? age : 0);
}, 0);

console.log(res);

Modified for names:

const items = [
{ "name":"John", "age":30, "city":"New York1"},
{ "name":"John1", "age":31, "city":"New York2"},
{ "name":"John2", "age":32, "city":"New York3"},
{ "name":"John3", "age":31, "city":"New York3"}]


const names = ["John", "john1"].map(n=>n.toLowerCase());
const res = items.reduce((sum, {name, age})=>{
  return sum + (names.includes(name.toLowerCase()) ? age : 0);
}, 0);

console.log(res);

Upvotes: 6

Nina Scholz
Nina Scholz

Reputation: 386756

You could use three steps

  1. get only the ages
  2. filter the ages with a Set
  3. add remaining values

var items = [{ name: "John", age: 30, city:" New York1" }, { name: "John1", age: 31, city: "New York2" }, { name: "John2", age: 32, city: "New York3" }, { name: "John3", age: 31, city: "New York3" }],
    ageArray = [30, 31],
    result = items
        .map(({ age }) => age)
        .filter(Set.prototype.has, new Set(ageArray))
        .reduce((a, b) => a + b, 0);

console.log(result);

A slightly different approach for different keys to filter and to add.

var items = [{ name: "John", age: 30, city:" New York1" }, { name: "John1", age: 31, city: "New York2" }, { name: "John2", age: 32, city: "New York3" }, { name: "John3", age: 31, city: "New York3" }],
    names = ['John', 'John2'],
    result = items
        .filter((s => ({ name }) => s.has(name))(new Set(names)))
        .map(({ age }) => age)
        .reduce((a, b) => a + b, 0);

console.log(result);

Upvotes: 3

Mr code.
Mr code.

Reputation: 307

const items = [
   { "name":"John", "age":30, "city":"New York1"},
   { "name":"John1", "age":31, "city":"New York2"},
   { "name":"John2", "age":32, "city":"New York3"},
   { "name":"John3", "age":31, "city":"New York3"}
];
const ages = [30,31];
const result = items.filter(o => ages.find(o2 => o.age === o2)).map(o3 => o3.age);
console.log(result)
const reducer = (accumulator, currentValue) => accumulator + currentValue;
console.log(result.reduce(reducer))

Upvotes: 1

adiga
adiga

Reputation: 35263

You can use reduce to do this in one line: 

const item = [{name:"John",age:30,city:"New York1"},{name:"John1",age:31,city:"New York2"},{name:"John2",age:32,city:"New York3"},{name:"John3",age:31,city:"New York3"}]
 ,ageArray = [30,31]
 ,total = item.reduce((sum, {age})=> sum += ageArray.includes(age) ? age : 0, 0);

console.log(total)

Upvotes: 2

Code Maniac
Code Maniac

Reputation: 37755

You can do it with reduce

var item= [{ "name":"John", "age":30, "city":"New York1"},{ "name":"John1", "age":31, "city":"New York2"},{ "name":"John2", "age":32, "city":"New York3"},{ "name":"John3", "age":31, "city":"New York3"}]

var ageArray=[30,31];


let op = item.reduce((o,c)=>{
  if( ageArray.includes(c.age) ) 
   { o+=c.age }
  return o;
},0)

console.log(op)

Upvotes: 3

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