files/en-us/web/javascript/reference/statements/debugger/index.md

metadata

title: debugger
slug: Web/JavaScript/Reference/Statements/debugger
page-type: javascript-statement
browser-compat: javascript.statements.debugger
sidebar: jssidebar

The debugger statement invokes any available debugging functionality, such as setting a breakpoint. If no debugging functionality is available, this statement has no effect.

Syntax

debugger;

Examples

Using the debugger statement

The following example shows code where a debugger statement has been inserted, to invoke a debugger (if one exists) when the function is called.

function potentiallyBuggyCode() {
  debugger;
  // do potentially buggy stuff to examine, step through, etc.
}

When the debugger is invoked, execution is paused at the debugger statement. It is like a breakpoint in the script source.

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• The Firefox JavaScript Debugger¶ in the Firefox source docs