JavaScript Statement Reference Manual

JavaScript Statements

In HTML, JavaScript statements are "commands" sent to the browser.

They tell the browser what to do.

The following JavaScript statement example tells the browser to output "Hello Dolly" into the HTML element with id="demo":

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

For more tutorials about statements, please refer to ourJavaScript Statements Tutorial。

JavaScript statements are usually identified by a statement identifier to determine the JavaScript operation to be performed.

Statement identifiers are reserved keywords and cannot be used as variable names.

The following table lists all JavaScript statements:

Statement	Description
break	Exits a switch statement or loop
continue	Skips the current iteration in a loop and continues with the next iteration in the loop
debugger	Stops execution of JavaScript and calls the debugging function
do ... while	Executes a block of statements and continues executing the block as long as the condition is true.
for	While the condition is true, the code block can be executed a specified number of times.
for ... in	Used to iterate over the properties of an array or object (performs a loop operation over the properties of an array or object).
function	Defines a function
if ... else ... else if	Used to execute different actions based on different conditions.
return	Exits a function and returns the value of the function
switch	Used to execute different actions based on different conditions.
throw	Throws (generates) an error.
try ... catch ... finally	Implements error handling, used together with catch.
var	Declares a variable.
while	When the condition is true, executes the statement block.

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