JavaScript Fundamentals · DOM · Lesson 23 of 48
Selecting Elements
Concept
Selecting Elements
document.querySelector and getElementById find elements on the page so you can read or update them.
querySelector accepts any valid CSS selector, so the same syntax you already use for styling — .class, #id, tag names — also works for finding elements in JavaScript.
- Explain the core idea behind Selecting Elements.
- Predict output before running a change.
- Test one realistic and one unusual input.
- Use the result to make the next decision.
- 1. Read one concept.
- 2. Change the example.
- 3. Run, compare, and explain.
- 4. Complete the challenge below.
Self-check before continuing
Without looking at the example, describe what changes when you modify one input in Selecting Elements. Then reopen the editor and prove your explanation with a small test.
You are ready to continue when you can predict, test, and explain the result.
Your turn
Describe, in a comment, how you would select every element with the class "card".
Ask about this lesson or your next move. The guide explains the path without taking the work away from you.
Ready for the next lesson?
Mark this lesson complete when you have finished the exercise.
Console