Check if item in string exist in array TS

Question

I have the following string

"0,2,4,5,6"

how can check if these numbers are in array

let daysweek = [
    { id: '0', name: 'Domingo' },
    { id: '1', name: 'Segunda' },
    { id: '2', name: 'Terça' },
];

Answer 1

Create a set of the ids in daysofweek , allowing you to easily check if an id is in daysweek .

let daysweek = [
   { id: '0', name: 'Domingo' },
   { id: '1', name: 'Segunda' },
   { id: '2', name: 'Terça'   },
];

let days = "0,2,4,5,6";

let set = new Set(daysweek.map( _ => _.id ))
let found_days = days.split(",").filter( day => set.has(day) );

console.log(found_days);

This is O(N). AlwaysHelping's answer and MarkCBall's answers are O(N ² ), which will fare far more poorly as the number of items in daysweek increases.

Answer 2

You can simply use Array#map and split function to do that.

Split() will remove all commas from your string and convert it an array .

And using map we get all the id's with and store them in a variable and check using Array#forEach which id's matched with string you have.

Live Demo:

 let daysweek = [{ id: '0', name: 'Domingo' }, { id: '1', name: 'Segunda' }, { id: '2', name: 'Terça' }, ]; let str = "0,2,4,5,6".split(',') //split the string let daysID = daysweek.map(y => y.id) //store the id's str.forEach(function(x){ let found = daysID.includes(x) console.log(x + " = " +found) //show true or false for each found id })

Answer 3

let daysweek = [
    { id: '0', name: 'Domingo' },
    { id: '1', name: 'Segunda' },
    { id: '2', name: 'Terça' },
];
const daysWeekIds = daysweek.map(obj=>obj.id)

const numbersAreInArray = "0,2,4,5,6".split(",").every(num=>daysWeekIds.includes(num))
console.log(numbersAreInArray)

Answer 4

I would like to thank you all, I found a example that met my need

daysweek2 = [
     'Domingo',
     'Segunda',
     'Terça',
     'Quarta',
     'Quinta',
     'Sexta',
     'Sábado',
];


function initDays() {
   return "0,2,4".split(',')
      .map(key => this.daysweek2[key]).join(',').split(',')
}


console.log(this.initDays());