JavaScript statements are programming instructions that you ask the computer to execute. Statements are separated by semicolons in JavaScript. Statements are comprised of values (literal and variable), operators, expressions, keywords and comments.
Literal values are things like numbers with a fixed value (12) or a string of text with a fixed value "Hello World!".
Variable values can, well, vary. The var keyword is used to declare (create, define) a variable.
var x:
Like most programming languages, JavaScript uses operators like +, -, *, /, etc. to do arithmetic operations. An equals sign is used to assign a value to a variable (a double equals sign is used to check if two things are equal or not).
2*3+4;
x = 12;
Expressions are combinations of values, variables and operators.
There are lots of keywords (like var) that have special meaning in JavaScript.
Just like with Python, HTML, and CSS, you can insert comments into JavaScript that you as the programmer can see (and anyone can see if they view the source), but don't display or do anything when the program is run.
Anything after // on a line or between /* and */ is treated as a comment.
Like most (all?) programming languages, JavaScript classifies date into different types. Some of the most common are number, boolean, string, array and object.
JavaScript data types are dynamic, meaning that a variable can start out as one type, then be changed to another dynamically.