How to transform value in array?

Question

I need to change the value I'm sending. An example of a array is:

0: {name: "One", value: 1}
1: {name: "Two", value: 2}
2: {name: "One", value: 3}
3: {name: "Two", value: 4}

Not important how length array can be. Any time is four object any time only two example:

0: {name: "One", value: 1}  
1: {name: "Two", value: 4}

Important is to need to convert value inside object

If I got:

0: {name: "One", value: 1}
1: {name: "Two", value: 2}
2: {name: "One", value: 3}
3: {name: "Two", value: 4}

I need to convert to

0: {name: "One", value: 'Value one'}
1: {name: "Two", value: 'Value two'}
2: {name: "One", value: 'Value three'}
3: {name: "Two", value: 'Value four'}

What i try:

data: convert(ArrayOfData)


convert(arr){
    const convertArr = ['Value one', 'Value two', 'Value three', 'Value four'];
    return value.map((value: any) => convertArr[value]);
    }

This no work i don't know why....

second try also no work....

 convert(arr){
  let resultArr = arr.map(arr => { 
   if (arr.value == 1) { 
     return  'Value one'
  }
   if (arr.value == 2) {
     return 'Value two'
   } 
 })
 return resultArr;
}

But according to the code, this should really work ...

zixiCat · Accepted Answer · 2021-04-20 09:02:35Z

1

Seems like you have a misunderstanding about Array.prototype.map()

const convertArr = [, 'Value one', 'Value two', 'Value three', 'Value four'];

value.map(({ name, value }) => ({
  name,
  value: convertArr[value],
}));

edited Apr 20, 2021 at 9:02

answered Apr 20, 2021 at 8:54

zixiCat

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5 Comments

TysonF Over a year ago

Friend with value: convertArr[value] no work propertly but with value: convertArr[value -1 ] work good. Why what is problem ?

zixiCat Over a year ago

Notice that const convertArr = [ , 'Va....], the length is 5

zixiCat Over a year ago

In this way, we don't need to -1 every time it traverses, and index also corresponds to its value

TysonF Over a year ago

Which way is better ?

zixiCat Over a year ago

Of course the current may, which reduces a little bit of calculation

DecPK · Accepted Answer · 2021-04-20 09:00:51Z

0

const values = {
  "1": "one",
  "2": "two",
  "3": "three",
  "4": "four",
};

const arr = [
  { name: "One", value: 1 },
  { name: "Two", value: 2 },
  { name: "One", value: 3 },
  { name: "Two", value: 4 },
];

const result = arr.map(({ name, value }) => {
  return { name, value: `Value ${values[value]}` };
});

console.log(result);

answered Apr 20, 2021 at 9:00

DecPK

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Comments

lbsn · Accepted Answer · 2021-04-20 09:01:41Z

0

See the docs about array.map():

The map() method creates a new array populated with the results of calling a provided function on every element in the calling array.

Since your provided function is always returning a string you'll get an array of strings. To get what you want you need instead to return a new item where the value property is changed the a string 'Value one' etc.

function convert(arr){
  let resultArr = arr.map(item => { 
   if (item.value == 1) { 
     return  {...item, value:'Value one'}
  }
   if (item.value == 2) {
     return  {...item, value:'Value two'}
   } 
 })
 return resultArr;
}

answered Apr 20, 2021 at 9:01

lbsn

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Comments

Alice Arkalykova · Accepted Answer · 2021-04-20 09:08:24Z

0

 public someFunc() {
    let arr = [{ name: 'One', value: '1' }, { name: 'Two', value: '2' }];
    arr = arr.map((item) => {
      item.value = `Value ${item.name.toLowerCase()}`;
      return item;
    });
  }

However you originally have value as a number and then convert it to a string, there will be a conflict. Also instead of my logic you can add any other logic, it should do

answered Apr 20, 2021 at 9:08

Alice Arkalykova

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