Get value of given key of object inside array of objects

Question

I want to pick the value of the given key and I did this using a ugly code: (I used two for loops to do a simple task)

const phrases = [
 {0: "i was sent", 1: "have you ever"},
 {2: "look", 3: "looked", 4: "looked", 5: "at", 6: "at"},
 {7: "someone", 8: "somebody", 9: "to earth", 10: "sam"},
 {11: "to protect"},
 {12: "us", 13: "to earth"},
 {14: "us", 15: "you"} 
];

const result = getSpanIDText(8); // get value of 8 im the above array
console.log(result);

function getSpanIDText(spanID) {

  for (let i = 0; i < phrases.length; i++) {
    const set = phrases[i]; // each object inside phrases array
    for (const [key, value] of Object.entries(set)) {
      if (parseInt(key) === spanID) {
        return value;
      }
    }

  }
}

I wonder if there is a more clear code not need two for loops to achive the same result?

RobbieD · Accepted Answer · 2020-08-26 15:58:52Z

1

This would eliminate the nested for loop, a little bit easier to read.

function getSpanIDText(spanID) {
     
     for(let phrase of phrases) {
      
        if(phrase[spanID]) {
           return phrase[spanID];
        }
      }
     }

edited Aug 26, 2020 at 15:58

answered Aug 26, 2020 at 15:52

RobbieD

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Comments

Mitya · Accepted Answer · 2020-08-26 15:50:07Z

1

I guess you could do something like this, provided you're sure each object will contain unique number keys.

let item = phrases.map(obj => Object.entries(obj)).flat().filter(arr => arr[0] == spanId);
return item.length ? item[0][1] : false;

Gives

getSpanIDText(8); //"somebody"

answered Aug 26, 2020 at 15:50

Mitya

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Comments

36ve · Accepted Answer · 2020-08-26 15:51:20Z

1

I don't know if it's really better but the following should work as well

function getSpanId(phrases, spanId) {
  return new Map(phrases.map(Object.entries).flat()).get(spanId)
}

answered Aug 26, 2020 at 15:51

36ve

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Vivek Jain · Accepted Answer · 2020-08-26 15:57:30Z

1

Try this.

const phrases = [

 {0: "i was sent", 1: "have you ever"},
 {2: "look", 3: "looked", 4: "looked", 5: "at", 6: "at"},
 {7: "someone", 8: "somebody", 9: "to earth", 10: "sam"},
 {11: "to protect"},
 {12: "us", 13: "to earth"},
 {14: "us", 15: "you"}
 
];
const result = getSpanIDText(8);

function getSpanIDText(id) {
  let output
  phrases.forEach(x => {
    return Object.keys(x).forEach(y => {
      if (+y === id) {
        output = x[y];
      }
    });
  });
  return output;
}
console.log(result);

answered Aug 26, 2020 at 15:57

Vivek Jain

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Comments

Dane Brouwer · Accepted Answer · 2020-08-26 15:59:56Z

1

You could use an optimized `reduce` function.

When the reduce function finds a matching key, it mutates the duplicated array to break out of the reduce loop.

const phrases = [
  {0: "i was sent", 1: "have you ever"},
  {2: "look", 3: "looked", 4: "looked", 5: "at", 6: "at"},
  {7: "someone", 8: "somebody", 9: "to earth", 10: "sam"},
  {11: "to protect"},
  {12: "us", 13: "to earth"},
  {14: "us", 15: "you"}
];

function getSpan(phrases, key) {
  return phrases.slice(0).reduce((acc, cv, i, arr) => {
    if (key in cv) {
      arr = [];
      return cv[key];
    }
    return acc
  }, undefined)
}

console.log(getSpan(phrases, 8)) // "somebody"
console.log(getSpan(phrases, 22)) // undefined

edited Aug 26, 2020 at 15:59

answered Aug 26, 2020 at 15:53

Dane Brouwer

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Get value of given key of object inside array of objects

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You could use an optimized `reduce` function.

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You could use an optimized reduce function.

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You could use an optimized `reduce` function.