Quadragésima primeira aula do curso Desenvolvedor web full stack.

window.alert()
https://developer.mozilla.org/pt-BR/docs/Web/API/Window/alert

console.log()
https://developer.mozilla.org/pt-BR/docs/Web/API/console/log

let – Variáveis
https://developer.mozilla.org/pt-BR/docs/Web/JavaScript/Reference/Statements/let

Operadores
https://developer.mozilla.org/pt-BR/docs/Web/JavaScript/Reference/Statements/let

Number
https://developer.mozilla.org/pt-BR/docs/Web/JavaScript/Reference/Global_Objects/Number

typeof
https://developer.mozilla.org/pt-BR/docs/Web/JavaScript/Reference/Operators/typeof

document.querySelector()
https://developer.mozilla.org/pt-BR/docs/Web/API/Document/querySelector

Concatenação
https://developer.mozilla.org/pt-BR/docs/Web/JavaScript/Reference/Operators/Addition

Funções
https://developer.mozilla.org/pt-BR/docs/Web/JavaScript/Reference/Functions

Eventos
https://developer.mozilla.org/pt-BR/docs/Web/JavaScript/Reference/Functions