debugger Statement (JavaScript)

Suspends execution.




You can place debugger statements anywhere in procedures to suspend execution. Using the debugger statement is similar to setting a breakpoint in the code.

The debugger statement suspends execution, but it does not close any files or clear any variables.


The debugger statement has no effect unless the script is being debugged.


This example uses the debugger statement to suspend execution for each iteration through the for loop.


To run this example, you must have a script debugger installed and the script must run in debug mode.

Internet Explorer 8 includes the JavaScript debugger. If you are using an earlier version of Internet Explorer, see How to: Enable and Start Script Debugging from Internet Explorer.

for(i = 1; i<5; i++) {  
   // Print i to the Output window.  
   Debug.write("loop index is " + i);  
   // Wait for user to resume.  


Supported in the following document modes: Quirks, Internet Explorer 6 standards, Internet Explorer 7 standards, Internet Explorer 8 standards, Internet Explorer 9 standards, Internet Explorer 10 standards, Internet Explorer 11 standards. Also supported in Store apps (Windows 8 and Windows Phone 8.1). See Version Information.

See Also

JavaScript Statements
Conditional Compilation