JavaScript syntax is the structure and rules that define how JavaScript code is written and understood by the browser. If the syntax is correct, the code runs smoothly. If not, JavaScript throws errors. Understanding syntax is the first and most important step in learning JavaScript.

JavaScript Statements

A statement is a line of code that performs an action. Most JavaScript programs are made up of many statements.

Statements usually end with a semicolon (;). While JavaScript can run without them, using semicolons helps avoid unexpected errors.

Variables and Values

Variables are used to store data. JavaScript provides three ways to declare variables:

  •  let → value can be updated

  • const → value remains fixed

Avoid using  var in modern JavaScript as it can cause unexpected behavior.

Case Sensitivity

JavaScript is case-sensitive, meaning uppercase and lowercase letters are treated differently


JavaScript Comments

Comments help explain code and are ignored during execution.

Comments make your code easier to understand and maintain.

Code Blocks and Curly Braces

Code blocks group multiple statements together using {}. They are commonly used in conditions and loops.


Indentation and Whitespace

JavaScript ignores extra spaces and line breaks, but proper formatting improves readability.

Clean and well-formatted code is easier to debug and understand.


Keywords

JavaScript has reserved words called keywords that have special meanings.

Examples include:

let, const, if, else, function, return

Conclusion

JavaScript syntax is simple but powerful. By learning how statements, variables, comments, and code blocks work together, you build a strong foundation for writing reliable JavaScript programs.