Node.js · Theory

Globals

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Globals

Meera only reaches for Globals when Meera walking through Globals has to stay correct in lab hour.

For Globals, an Express route is in play. Don’t blame it until you have traced Meera walking through Globals.

Without Globals, lab hour gets messy and Meera walking through Globals is hard to trust.

Meera ships Globals in lab hour. That is the use case worth saying.

Don’t do this with Globals — copy-pasting Globals without a dry-run. Interviewers spot it in ten seconds.

Place Globals next to nearby Node.js work — one Globals step Meera can write from memory is the link.

Viva for Globals: what it is → one Globals step Meera can write from memory → the mistake (copy-pasting Globals without a dry-run).

Exam tip

Board: Meera walking through Globals. Dry-run Globals. Name the trap: copy-pasting Globals without a dry-run.

Example

// Globals
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));

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

Short notes

DefGlobals — Meera uses it for Meera walking through Globals in lab hour.
RuleGlobals → one Globals step Meera can write from memory.
RememberGlobals + an Express route (lab hour).
UseGlobals in lab hour (Meera walking through Globals).
TrapGlobals — copy-pasting Globals without a dry-run.
ExGlobals → Meera walking through Globals.

// Globals 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));

Globals

Example

Short notes

Questions

Globals

Example

Short notes

Questions