JavaScript Statements Reference
JavaScript Statements
In HTML, JavaScript statements are "instructions" to be "executed" by the web browser.
This statement tells the browser to write "Hello Dolly." inside an HTML element with id="demo":
For a tutorial about Statements, read our JavaScript Statements Tutorial.
JavaScript Statement Identifiers
JavaScript statements often start with a statement identifier to identify the JavaScript action to be performed.
Statement identifiers are reserved words and cannot be used as variable names (or any other things).
The following table lists all JavaScript statements:
| Statement | Description |
|---|---|
| break | Exits a switch or a loop |
| const | Declares a variable with a constant value |
| class | Declares a class |
| continue | Breaks one iteration (in the loop) if a specified condition occurs, and continues with the next iteration in the loop |
| debugger | Stops the execution of JavaScript, and calls (if available) the debugging function |
| do ... while | Executes a block of statements and repeats the block while a condition is true |
| for | Loops through a block of code a number of times |
| for ... in | Loops through the properties of an object |
| for ... of | Loops through the values of an iterable object |
| function | Declares a function |
| if ... else ... else if | Marks a block of statements to be executed depending on a condition |
| let | Declares a variable inside brackets {} scope |
| return | Stops the execution of a function and returns a value from that function |
| switch | Marks a block of statements to be executed depending on different cases |
| throw | Throws (generates) an error |
| try ... catch ... finally | Marks the block of statements to be executed when an error occurs in a try block, and implements error handling |
| var | Declares a variable |
| while | Marks a block of statements to be executed while a condition is true |
