Node.js · Theory

Console

Theory

5/723

Console

console.log prints. console.error for errors (stderr). console.table for a small array of objects. In production, a logger (pino/winston) is better than log in a hot loop.

Trap — console.log(hugeObject) in a request handler thousands of times.

Exam tip

console.log('marks', marks);

Example

// Console
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));

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

Short notes

Defconsole.log / error / table.
RuleLogs for debug. Logger in production.
TrapLogging in a hot loop.

Node.js · Theory

Console

← All stacks

Theory

5/723

Console

console.log prints. console.error for errors (stderr). console.table for a small array of objects. In production, a logger (pino/winston) is better than log in a hot loop.

Trap — console.log(hugeObject) in a request handler thousands of times.

Exam tip

console.log('marks', marks);

Example

// Console
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));

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

Short notes

Defconsole.log / error / table.
RuleLogs for debug. Logger in production.
TrapLogging in a hot loop.

Console

Example

Short notes

Questions

Console

Example

Short notes

Questions