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 ...

Answer 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],
}));

• TysonF: Friend with value: convertArr[value] no work propertly but with value: convertArr[value -1 ] work good. Why what is problem ?
• zixiCat: Notice that const convertArr = [ , 'Va....], the length is 5
• zixiCat: In this way, we don't need to -1 every time it traverses, and index also corresponds to its value
• TysonF: Which way is better ?
• zixiCat: Of course the current may, which reduces a little bit of calculation

Answer 2

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);

Answer 3

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;
}

Answer 4

 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