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":

document.getElementById("demo").innerHTML = "Hello Dolly.";

For a tutorial about Statements, read our JavaScript Statements Tutorial.

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 statement identifiers:

Statement	Description
break	Exits a switch or a loop
class	Declares a class
const	Declares a variable with a constant value
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
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