Node.js · Theory

First Example

Theory

4/723

First Example

console.log('Hello Node'); save as hello.js; run node hello.js. That is first example. Then a tiny server: require('http') or import, listen on 3000, res.end('Hello').

If node is not recognised, Node isn’t installed or PATH is old — open a new terminal.

Trap — writing <script> in a .js file you run with node. That’s browser HTML.

Exam tip

console.log('Hello Node'); node hello.js

Example

// First Example
const users = [
  { id: 1, name: "Asha" },
  { id: 2, name: "Ravi" },
];

function findUser(id) {
  return users.find((u) => u.id === id) ?? null;
}

console.log(findUser(2));
console.log(users.map((u) => u.name));

First Example: find user 2, then list names. Say both prints.

Short notes

Defnode hello.js prints Hello.
RuleNew terminal after install.
TrapBrowser HTML inside Node files.

Node.js · Theory

First Example

← All stacks

Theory

4/723

First Example

console.log('Hello Node'); save as hello.js; run node hello.js. That is first example. Then a tiny server: require('http') or import, listen on 3000, res.end('Hello').

If node is not recognised, Node isn’t installed or PATH is old — open a new terminal.

Trap — writing <script> in a .js file you run with node. That’s browser HTML.

Exam tip

console.log('Hello Node'); node hello.js

Example

// First Example
const users = [
  { id: 1, name: "Asha" },
  { id: 2, name: "Ravi" },
];

function findUser(id) {
  return users.find((u) => u.id === id) ?? null;
}

console.log(findUser(2));
console.log(users.map((u) => u.name));

First Example: find user 2, then list names. Say both prints.

Short notes

Defnode hello.js prints Hello.
RuleNew terminal after install.
TrapBrowser HTML inside Node files.

First Example

Example

Short notes

Questions

First Example

Example

Short notes

Questions