I have an array of objects like below, where I want to calculate the sum of job_security, skill_development and company_culture these fields.

reviews = [
  {
      id: 1,
      job_security: '2.0',
      skill_development: '3.0',
      company_culture: '4.0',
      is_anonymous: false,
      pros: 'Test 1...',
      cons: "Test 1...",
      created_at: '2022-10-19T19:07:18.000Z',
  },
  {
      id: 2,
      job_security: '3.0',
      skill_development: '1.0',
      company_culture: '2.0',
      is_anonymous: false,
      pros: 'Test 2...',
      cons: "Test 2...",
      created_at: '2022-10-19T19:07:25.000Z',
  },
  {
      id: 3,
      job_security: '4.0',
      skill_development: '1.0',
      company_culture: '2.0',
      is_anonymous: false,
      pros: 'Test 3...',
      cons: "Test 3...",
      created_at: '2022-10-19T19:07:35.000Z',
  }
]

I am expecting an output like this, where total sums of all the fields will return as an object

{
   job_security: '4.0',
   skill_development: '6.0',
   company_culture: '7.0',
}

This is what I have done :

const filteredKeys = [
  'job_security'
  'company_culture',
  'skill_development',
];

reviews.forEach((review: any) => {
   Object.keys(review).reduce(
      (accu: any, key: string) => {
         if (filteredKeys.includes(key)) {
            const rating = Number(review[key]);
            accu[key] = accu[key] || rating;
            accu[key]  = rating;
         }
         return accu;
      },
      Object.create(null)
   );
});

CodePudding user response：

simply use Array.reduce() method :

const reviews = [{id: 1,job_security: '2.0',skill_development: '3.0',company_culture: '4.0',is_anonymous: false,pros: 'Test 1...',cons: "Test 1...",created_at: '2022-10-19T19:07:18.000Z',},{id: 2,job_security: '3.0',skill_development: '1.0',company_culture: '2.0',is_anonymous: false,pros: 'Test 2...',cons: "Test 2...",created_at: '2022-10-19T19:07:25.000Z',},{id: 3,job_security: '4.0',skill_development: '1.0',company_culture: '2.0',is_anonymous: false,pros: 'Test 3...',cons: "Test 3...",created_at: '2022-10-19T19:07:35.000Z',}];

const sums = reviews.reduce( (s,e,i,{[i 1]:eNext})=>
  {
  Object.keys(s).forEach( k => s[k]  =  e[k] );
  if (!eNext) // for the last (no next element), change values to string
    Object.keys(s).forEach( k => s[k] = s[k].toFixed(1) );
  return s
  }
  ,{ job_security: 0, skill_development: 0, company_culture: 0 });
  
  
console.log( sums )

CodePudding user response：

You could do something like this

const reviews = [
  {
      id: 1,
      job_security: '2.0',
      skill_development: '3.0',
      company_culture: '4.0',
      is_anonymous: false,
      pros: 'Test 1...',
      cons: "Test 1...",
      created_at: '2022-10-19T19:07:18.000Z',
  },
  {
      id: 2,
      job_security: '3.0',
      skill_development: '1.0',
      company_culture: '2.0',
      is_anonymous: false,
      pros: 'Test 2...',
      cons: "Test 2...",
      created_at: '2022-10-19T19:07:25.000Z',
  },
  {
      id: 3,
      job_security: '4.0',
      skill_development: '1.0',
      company_culture: '2.0',
      is_anonymous: false,
      pros: 'Test 3...',
      cons: "Test 3...",
      created_at: '2022-10-19T19:07:35.000Z',
  }
]

const filters =  [
  'job_security',
  'company_culture',
  'skill_development',
];
const output = reviews.reduce((acc, next)=> {
  for (let filter of filters){
      if (!(filter in next)) throw new Error(`Cannot find ${filter} in object`)
      if (!(filter in acc)) acc[filter] = 0;
      acc[filter] =  next[filter];
  }
  return acc;
}, {})

CodePudding user response：

You can use reduce() to do it

let reviews = [
  {
      id: 1,
      job_security: '2.0',
      skill_development: '3.0',
      company_culture: '4.0',
      is_anonymous: false,
      pros: 'Test 1...',
      cons: "Test 1...",
      created_at: '2022-10-19T19:07:18.000Z',
  },
  {
      id: 2,
      job_security: '3.0',
      skill_development: '1.0',
      company_culture: '2.0',
      is_anonymous: false,
      pros: 'Test 2...',
      cons: "Test 2...",
      created_at: '2022-10-19T19:07:25.000Z',
  },
  {
      id: 3,
      job_security: '4.0',
      skill_development: '1.0',
      company_culture: '2.0',
      is_anonymous: false,
      pros: 'Test 3...',
      cons: "Test 3...",
      created_at: '2022-10-19T19:07:35.000Z',
  }
]

let keys =  [
  'job_security',
  'company_culture',
  'skill_development',
];
let result = reviews.reduce((a,v) =>{
  keys.forEach(k =>{
    a[k] = (a[k]??0)   ( v[k]) 
   })
  return a
},{})
console.log(result)