Variables and values

What this means

A variable is a named place for a value. A value can be text, a number, true or false, an array, an object, or other data.

In beginner terms, this topic answers one practical question: "What should I write, and why does React care about it?" Do not try to memorize the syntax first. First understand the idea, then connect the syntax to that idea.

Why it matters

Programs need memory. Variables let you give meaning to data so later code can use it clearly.

When you build real React screens, this idea helps you decide where data should live, what the user should see, and what should happen after an interaction. That is why this lesson is part of the main path instead of being an optional detail.

Step by step

1. Notice the UI problem this topic solves. 2. Look at the smallest possible example. 3. Change one value and predict what should appear. 4. Run the example and compare the result with your prediction. 5. Use the practice task before moving on.

Small example

const name = "Ada";
let score = 0;

Common mistake

Do not use unclear names like x or data2 when a meaningful name like lessonTitle explains the value.

Practice task

Create variables for your name, current lesson, and completed status. Show them on the page.

Remember this

Good variable names make code easier to read.