Get element

Selecting Elements

syntax

document.querySelector(selector)
document.querySelectorAll(selector)
document.getElementById(id)

example

const header = document.querySelector("h1");
const buttons = document.querySelectorAll(".btn");
const main = document.getElementById("main-content");

// querySelectorAll returns a static NodeList
buttons.forEach(btn => {
  console.log(btn.textContent);
});

Note querySelector returns the first match or null. querySelectorAll returns a static NodeList (does not auto-update). Use Array.from() if you need full array methods.

PYPython

Indexing & Negative Indexing

PY · Lists

syntax

items[index]
items[-index]

example

fruits = ["apple", "banana", "cherry", "date"]
print(fruits[0])
print(fruits[-1])
print(fruits[-2])

output

apple
date
cherry

Note Index 0 is the first element, -1 is the last. Accessing an index beyond the list length raises IndexError.

JSJavaScript

PYPython