Conditional for verification

Question

I’m Creating a File js with a jquery. In this file I need to make a conditional or several conditional that check a certain amount of numbers. If the variable x is one of the numbers 1,3,5,6,7,9,10, one must show the word Yes, but if the numbers are 2,4,8,11,12,17, one must show the word no. How can I do that?

Answer 1

Use the function $.inArray() jQuery

var sim = [1, 3, 5, 6, 7, 9, 10];
var nao = [2, 4, 8, 11, 12, 17];

var x = 2;

if ($.inArray(x, sim) != -1) {
  document.write('sim');  
} else if ($.inArray(x, nao) != -1) {
  document.write('nao');
}

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

Answer 2

You can use the .index(), You don’t need jQuery. If you are going to repeat this check several times you can do a function for this.

I suggest to store these numbers in arrays:

var numerosA = [1,3,5,6,7,9,10];
var numerosB = [2,4,8,11,12,17];

and then check the new number with these:

numerosA.indexOf(1) != -1 // true
numerosA.indexOf(2) != -1 // false
numerosB.indexOf(1) != -1 // false
numerosB.indexOf(2) != -1 // true

The .index() gives the position of that number within the array. If the number does not exist in the array, it will give -1.

You can also use a ternary for this. Then you can do:

var resultado = numerosA.indexOf(seuNumero) != -1 ? 'Sim' : 'Não';

Example applied to a function, in this example giving a third answer to erroneous cases:

var numerosA = [1, 3, 5, 6, 7, 9, 10];
var numerosB = [2, 4, 8, 11, 12, 17];

function verificar(nr) {
    if (numerosA.indexOf(nr) != -1) return 'Sim!';
    else if (numerosB.indexOf(nr) != -1) return 'Não!';

    return 'Não existe em nenhuma...';
}

alert(verificar(1)); // Sim!
alert(verificar(2)); // Não!
alert(verificar(500)); // Não existe em nenhuma...

Answer 3

If you prefer a Jquery solution, you can use $.inArray()

if ($.inArray(x, [1,3,5,6,7,9,10]) !== -1){
    console.log('Sim');
}else if($.inArray(x, [2,4,8,11,12,17]) !== -1){
    console.log('Não');
}