JSFiddle - React, Tailwind, and code Playground

by gustavox

HTML

<input class="form-control" type="text" maxlength="10" placeholder="dd/mm/aaaa" onkeyup="formatar('##/##/####', this)" name="Tinsem3" id="Cinsem">

JavaScript

function formatar(mascara, documento) {
                    var i = documento.value.length;
                    var saida = mascara.substring(0, 1);
                    var texto = mascara.substring(i);
                    if (texto.substring(0, 1) != saida) {
                        documento.value += texto.substring(0, 1);
                    }
                }