Javascript - Splitting into an array

Question

I’m trying to solve an exercise, and I’m having a hard time finding out where I’m going wrong, some hint?

Exercise :

Program a function buscarDivisivelPor which receives two parameters, one array of numbers and a test number, returning the first number of the array that is divisible by the given number and other than zero. If no array pass the test, return the text "No valid number found!".

My code :

function buscarDivisivelPor(array, num) {
  for ( var i = 0; i < array.length; i++) {
    if( (array[i] % num ) && (!0) ){
      console.log(array[i])
      break
    } else {
      console.log("Nenhum número válido encontrado!")
    }
  }    
}


//Exemplo de array : [0, 9, 4, 7, 128, 42, -1, 301, -5]  num : 2 
//A resposta deveria ser 4

Answer 1

Hello, try using this code and pay attention to my comments! Good studies!

function buscarDivisivelPor(array, num) {
      
      for(var i=0; i<=array.length;i++){
         
         if (array[i] % num == 0 && array[i] != 0) { /* resto zero e valor do array tem que ser diferente de 0*/
            
             return array[i]; /* não dá para retornar um contador, então a contagem vai parar no primeiro valor que atenda a condição*/
          } 
             
       } 
       return "Nenhum número válido encontrado!"; /* O return precisa ser fora da condição e do loop porque dessa forma a frase será impressa só uma vez, isto é, quando o array inteiro não atender os requisitos*/
    }

Answer 2

Your problem is conditional, the challenge asks you to print the divisible number, for you to know if a number is divisible by 2 it is necessary to check if the rest is zero.

In the code:

if (array[i] % num === 0) {

}

The number must be non-zero, to verify this condition, you used if (!0) {} and that probation will always be true, since 0 is considered false.

What you need is to check if the number is non-zero.

In the code:

if (array[i] !== 0) {

}

Your code would look like this:

function buscarDivisivelPor(array, num) {
  for (var i = 0; i < array.length; i++) {
    if((array[i] % num === 0) && (array[i] !== 0) ){
      console.log(array[i]);
    
      break
    }
  }    
}

Solving the challenge:

function searchFirstNumberDivisibleBy(divider, numbers = []) {
    const firstNumberFound = numbers.find(
      number => number % divider === 0 && number !== 0,
    );

    if (!firstNumberFound) {
      throw new Error('Nenhum número válido encontrado!');
    }

    return firstNumberFound;
}