How to return the last record of an array with Javascript or jQuery?

Question

I’m making a custom search filter where the user can select the brand and product features and I return their id.

But I wanted to return only the last record of mine arrays where they contain all the information I need.

I just need to return the last record presented in the console as in the image below. Ex: mark=25,30,53 and feature:10:35:4

Follows the code:

<a href="#" class="filter-link">
  <div class="label_check">
       <input type="checkbox" id="marca-4" class="filter-check" data-tipo="marca?4" value="4">
       <div class="filter-pretty-check"></div>
       <span class="filter-desc">Nokia</span>
  </div>
</a>

    $('#filtrar-opcoes').on('click',function(){                    
                var tipos = [];
                var caracteristicas = [];
                $.each(($("input[type=checkbox]:checked")),function(index, obj){                                                
                    var $tipo =  $(obj).attr('data-tipo');                                                                                   
                    if($tipo.split('?')[0] == 'marca'){
                        tipos.push($tipo.split('?')[1]);                                    
                        var firstPartUrl = $tipo.split('?')[0] + '=' + tipos.join();                                                                
                        console.log(firstPartUrl);                                                                                                                    
                    }
                    if($tipo.split('?')[0] == 'caracteristica'){
                        caracteristicas.push($tipo.split('?')[1]);                            
                        var lastPartUrl = $tipo.split('?')[0] + '=' + caracteristicas.join(':');
                        console.log(lastPartUrl);                            
                    }
                });
            });

Answer 1

You can do this using pure javascript, this way:

var array = [1, 2, 3, 4, 5];
var ultimo = array[array.length - 1];
document.write(ultimo);

If you prefer to use jQuery, you can do something like:

var array = [1, 2, 3, 4];
var ultimo = $(array).get(-1);
document.write(ultimo);

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

Answer 2

Another way to get the last element of array, whereas it does not remove the last element of the array, would be using the function slice pointing to the last element through the -1.

a = [1, 2, 3]
document.write(a.slice(-1)[0])

slice return the last element of array within a array. That’s why we use the index 0.

Behold:

a.slice(-1); // Imprime: [3]

Answer 3

Another way would also be using the function pop. It removes the last element of the vector and returns it. I don’t know if it would be recommended in your case.

See working here.

var vetor1 = new Array(1, 2, 3, 2, 7);
var ultimo = vetor1.pop();
document.write(ultimo);

Answer 4

If it is something recurring in the project, you can extend the Array by implementing a method for it:

Array.prototype.get = function(index) {
    return this[index < 0 ? this.length + index : index];
};

So, anywhere, to search for the last element just do:

arr.get(-1)

It applies the same logic described in LINQ, but in a way global, no need to repeat the code whenever you access the last element.

See working:

Array.prototype.get = function(index) {
    return this[index < 0 ? this.length + index : index];
};

Array.prototype.last = function(index) {
    return this.get(-1);
};

Array.prototype.first = function(index) {
    return this[0];
};

const arr = [1, 2, 3];

console.log('Último elemento com get:', arr.get(-1));
console.log('Último elemento com last:', arr.last());
console.log('Primeiro elemento com first:', arr.first());

Answer 5

Hello!

I did it this way:

//Coloque a última fruta da array em uma variável, sem remover a mesma do array

var frutas = ['Banana','Maçã','Pera','Uva','Melancia']

//Varredura para achar o último item do array (frutas.length - 1)

for (var item = 0; item < frutas.length; item++) {
    if (frutas[item] === frutas[frutas.length - 1]) {
        var ultimaFruta = frutas[item]
        console.log(ultimaFruta)
    }
}