It is returning the data below 2000, but I need to know what positions this data is in. Javascript

Question

var veiculos = [valores informados pelo usuário]

var teste = veiculos.filter(carro => carro <= 2000)

res.innerHTML += `${teste}, </br>

`

Answer 1

You can pass a second parameter in the function that is passed as parameter in the filter to pick up the index. Example:

const veiculos = [9999, 1000, 2000, 3000, 4000, 5000];
const indexes = [];
var teste = veiculos.filter((carro, index) => {
  if (carro <= 2000) {
    indexes.push(index);
    return true;
  }
  
  return false;
});

console.log(teste, indexes);

Answer 2

Wellyngton,

Since you want to return the index, perhaps using the filter is not the best option, although it is possible.

See these examples, using reduce and also a more traditional for, both resulting in an array containing the indexes you want to filter:

let veiculos = [2001,2000,1999,3000,4000,1000,7000,8000,9999,100,500,300,800];

//Reduce
let indicesReduce = veiculos.reduce( (acumulador,carro, indice) => {
  if (carro <= 2000) {
    acumulador.push(indice);
  }
  return acumulador;
}, [] );

console.log("Reduce:", indicesReduce);

//For
let indicesFor = [];

for (const [indice,carro] of veiculos.entries()) {
  if(carro <= 2000) {
    indicesFor.push(indice);
  }
}

console.log("For:", indicesFor);

References:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for...of

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/reduce