Values, literals, identifiers and comments.
✍️ 3 exercises + code challenge in this lessonJavaScript syntax is the set of rules for writing programs.
10.5, "Ali", true.let x = 10;_ or $ and are case-sensitive: total and Total are different.firstName, totalPrice.// single-line comment and /* multi-line comment */. Comments explain code and can disable lines while testing.
Mastering JavaScript Syntax & Comments helps you write clean and reliable JavaScript code. Follow standard conventions, test edge cases, and keep logic simple. Try running the code example below and complete the exercises to build confidence.
<pre id="out"></pre>
<script>
const log = (...a) => document.getElementById("out").textContent += a.join(" ") + "\n";
// This is a single-line comment
let firstName = "Sara"; // camelCase identifier
let FirstName = "Ayesha"; // a different variable (case-sensitive)
/*
This is a multi-line comment.
log("This line does not run");
*/
log(firstName, "and", FirstName);
</script>Check what you learned in “JavaScript Syntax & Comments”.
Write a single-line comment.
This line is ignored
Are firstName and FirstName the same variable?
Two lines print. Turn the second log into a comment so only "Keep me" is printed.
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