JavaScript Statements

JavaScript Statements

A program is a list of statements that the computer executes in order.

What is a statement?

A statement is one instruction. It can do things like declare a variable, make a decision, or call a function:

let message = "Hello";   // statement 1
document.write(message); // statement 2

Statement keywords

Common JavaScript statement keywords:

• let, var, const declare variables.
• if, else, switch make decisions.
• for, while, do create loops.
• function and return define and return from functions.
• break and continue control loops.
• try, catch, throw handle errors.

Statement blocks

Statements can be grouped in blocks with curly braces { and }:

if (age > 18) {
  console.log("Adult");
}

Execution order

JavaScript runs statements top to bottom, one at a time. This is called sequential execution.

The semicolon rule

Each statement usually ends with a semicolon. The semicolon tells JavaScript where one statement ends and the next begins.

TL;DR

• A statement is one instruction.
• Keywords like if, for, and function start statements.
• Blocks group statements with curly braces.
• Statements run top to bottom.
• End statements with semicolons.