JavaScript Quick Reference

Use this while practicing lessons

js-quick-ref.txtCHEAT SHEET

Conditionals

if (age >= 18) {
  console.log("Adult");
} else {
  console.log("Minor");
}

Loops

for (let i = 0; i < 5; i++) {
  console.log(i);
}

Array Methods

const nums = [1, 2, 3, 4];
const doubled = nums.map((n) => n * 2);
const even = nums.filter((n) => n % 2 === 0);
const sum = nums.reduce((s, n) => s + n, 0);

Try/Catch

try {
  JSON.parse("{ bad }");
} catch (error) {
  console.error(error.message);
}

Practice Hub Examples