JavaScript / Node.js

info

Versao: Node.js 20.19.6 Rootfs: 700 MB Tipo: Interpretada

Overview

JavaScript e a linguagem de programacao mais popular do mundo. Node.js permite executar JavaScript no servidor com performance excepcional.

Especificacoes

Propriedade	Valor
Versao	20.19.6 (LTS)
Comando	node
Extensao	.js
Rootfs Size	700 MB
Tempo de Execucao	~150ms

Modulos Disponiveis

A instalacao padrao inclui todos os modulos built-in do Node.js:

• fs, path, os
• http, https, url
• crypto, buffer
• stream, events

warning

Pacotes npm externos nao estao disponiveis na instalacao padrao.

Exemplos

Hello World

Simple Hello World output

console.log("Hello World");

Funcoes Assincronas

Async function with Promise

async function fetchData() {
    return new Promise(resolve => {
        setTimeout(() => resolve("Data loaded!"), 100);
    });
}

fetchData().then(console.log);

Manipulacao de Arrays

Array map and reduce operations

const numbers = [1, 2, 3, 4, 5];
const doubled = numbers.map(n => n * 2);
const sum = numbers.reduce((a, b) => a + b, 0);

console.log("Doubled:", doubled);
console.log("Sum:", sum);

Classes

Calculator class with basic operations

class Calculator {
    add(a, b) { return a + b; }
    subtract(a, b) { return a - b; }
    multiply(a, b) { return a * b; }
    divide(a, b) { return a / b; }
}

const calc = new Calculator();
console.log(calc.multiply(6, 7));

TypeScript

TypeScript tambem e suportado via ts-node:

TypeScript interface and type safety example

interface User {
    name: string;
    age: number;
}

const user: User = { name: "Alice", age: 30 };
console.log(`${user.name} is ${user.age} years old`);

Limitacoes

• Sem acesso a rede (fetch/http requests bloqueados)
• Sem acesso a sistema de arquivos externo
• Timeout padrao de 10 segundos
• Memoria limitada a 512MB

Best Practices

Best Practices

• Avoid external dependencies — Use only built-in modules available in Node.js
• Handle promises properly — Use async/await with try/catch for error handling
• Prefer synchronous operations — For more predictable code execution
• Output to stdout/stderr — Use console.log() and console.error() for output