Javascript is awesome

Javascript logo.

I’m very excited about studying Javascript on the mission of expand my knowledges at front-end. The principal goal is use Javascript at my Java back-end projects.

So, two things I really liked on javascript so far is:

  1. template string;
  2. spread operator.

The first concept lets a array be used as params of methods, on a very easy and functional way.

The second one helps on format messages that uses dynamics values, as variables. We can just reference the value inside a string pattern, marked with the ` character.

See the example…

As we follow, in the example below we have a constructor that receives three params but on the View we have just one field. Ok, that is not right, but works for now.


    <label>Informações do arquivo</label>
    <input class="dados-arquivo" placeholder="formato: nome/tamanho/tipo">

    <button onclick="arquivoController.envia()"  >Enviar</button>

class Arquivo {

    constructor(nome, tamanho, tipo) {
        this._nome = nome;
        this._tamanho = tamanho;
        this._tipo = tipo;

So we can use the two concepts above to catch a fancy solution, like this:

envia() {
    let dados = this._inputDados.value.toUpperCase().split('/');
    let arquivo = new Arquivo(...dados); // the spread operador
    console.log(`Dados do arquivo: ${arquivo.nome}, ${arquivo.tamanho}, ${arquivo.tipo}`); // template string

We still can encapsulate the solution in a helper class, of builder pattern, that generates a static method that returns the model:

ArquivoHelper {

    static cria(informacao) {
        return new Arquivo(...informacao.toUpperCase().split('/'));

So, let me move on to the next chapter. So long, fair well.

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