How to do a function to tell when an array is empty?

Question

How to do a function to tell when an array is empty?

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#1 by (9 votes)
#2 by (2 votes)
#3 by (2 votes)

3

I need a function that tells you when an array is empty. But the way I tried to do it is not right, can anyone help me?

function validaCampo(){    
   if(count(dias[])==0)
        {
        alert("O Campo Dias disponíveis é obrigatório!");
        return false;
        }
      else
      return true;
}

javascript array

asked by anonymous 11.09.2017 / 22:14

3 answers

2

You have it ready:

function validaCampo() {    
   if(dias.length == 0) {
        alert("O Campo Dias disponíveis é obrigatório!");
        return false;
   }
   return true;
}

Documentation .

11.09.2017 / 22:17

2

Check the length of the array.

vetor = [];
vetor1 = ['item1'];

validaVetor(vetor);
validaVetor(vetor1);

function validaVetor(vetor){
  if(vetor.length>0){
    console.log("Vetor populado");
  }else{
    console.log("Vetor vazio");
  }
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

11.09.2017 / 22:18

Uncaught TypeError: object is not a function. Clone html and Back button [closed] What is the difference between a one-dimensional and two-dimensional matrix?

score 9 · Accepted Answer

JavaScript does not have count() , this is PHP. You can use .length like this:

if(dias.length == 0){
    // etc
}

If you only want a Boolean you can do this:

function validaCampo() {
  const valido = dias.length > 0;
  if (!valido) alert("O Campo Dias disponíveis é obrigatório!");
  return valido;

}