CODEWITHSUNDEEP
javascript
Siva Pradhan
Siva Pradhan

Reputation: 861

Map key of object with array of object value

Suppose I have an array of object as:

const bookDetails = [{"author":"john","email":"[email protected]","readingTime":"121"}, 
                 {"author":"romero","email":"[email protected]","readingTime":908}, 
                 {"author":"romero","email":"[email protected]","readingTime":1212},
                 {"author":"buck","email":"[email protected]","readingTime":1902}, 
                 {"author":"buck","email":"[email protected]","readingTime":12125}, 
                 {"author":"romero","email":"[email protected]","readingTime":500},
                 {"author":"john","email":"[email protected]","readingTime":10},
                 {"author":"legend","email":"[email protected]","readingTime":12}
                 {"author":"john","email":"[email protected]","readingTime":1890}]

I have an object as: const toMatch = {"[email protected]":1212,"[email protected]":1248,"[email protected]":909}

I want to replace emailId with corresponding author.

So my expected O/P should be: {"romero":1212,"john":1248,"buck":909}

If anyone needs any further information please let me know.

Upvotes: 1

Views: 88

Answers (3)

Akhil
Akhil

Reputation: 879

You can generate a new object by iterating over bookDetails and look up the values from toMatch

Like this

const bookDetails=[{"author":"john","email":"[email protected]","readingTime":"121"},{"author":"romero","email":"[email protected]","readingTime":908},{"author":"romero","email":"[email protected]","readingTime":1212},{"author":"buck","email":"[email protected]","readingTime":1902},{"author":"buck","email":"[email protected]","readingTime":12125},{"author":"romero","email":"[email protected]","readingTime":500},{"author":"john","email":"[email protected]","readingTime":10},{"author":"legend","email":"[email protected]","readingTime":12},{"author":"john","email":"[email protected]","readingTime":1890}]
const toMatch = {"[email protected]":1212,"[email protected]":1248,"[email protected]":909}

const result = {};

for (const detail of bookDetails) {
    const {email, author} = detail;
    if (email in toMatch) {
        result[author] = toMatch[email];
    }
}

console.log(result);

Upvotes: 2

Sebastian Ciocarlan
Sebastian Ciocarlan

Reputation: 300

There you go, I'm 100% you can do this easier, but this is the fastest response that came to my mind:

function changeData(bookDetails){
    let returnableObject = {};
    bookDetails.forEach(book => {
        returnableObject[book.author] = book.readingTime
})
return returnableObject;
}

*EDIT -> This would work if your Author name IS UNIQUE if the author name is not unique you should change the name or maybe use an array of objects, not an object with multiple values...

*EDIT 2 -> I think I didnt understand your question.

Upvotes: 2

The Bomb Squad
The Bomb Squad

Reputation: 4337

Ah, you want to matching names from emails based on the array of objects. Is that right? If so..

const bookDetails=[{"author":"john","email":"[email protected]","readingTime":"121"},{"author":"romero","email":"[email protected]","readingTime":908},{"author":"romero","email":"[email protected]","readingTime":1212},{"author":"buck","email":"[email protected]","readingTime":1902},{"author":"buck","email":"[email protected]","readingTime":12125},{"author":"romero","email":"[email protected]","readingTime":500},{"author":"john","email":"[email protected]","readingTime":10},{"author":"legend","email":"[email protected]","readingTime":12},{"author":"john","email":"[email protected]","readingTime":1890}]

function namesMap(object,list){
  //to save complexity(assuming the array is huge), I'd just loop through the list once to get the data I need
  var obj={} //relates emails to names
  list.forEach(item=>{
    obj[item.email]=item.author
  })
  var toReturn={}
  Object.keys(object).forEach(email=>{
    toReturn[obj[email]]=object[email] //email to name conversion
  })
  return toReturn
}

//example usage
const toMatch = {"[email protected]":1212,"[email protected]":1248,"[email protected]":909}
console.log(namesMap(toMatch,bookDetails))

Upvotes: 2

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