The debugger statement invokes any available debugging functionality, such as setting a breakpoint. If no debugging functionality is available, this statement has no effect.
debugger;
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.
| Specification | Status | Comment |
|---|---|---|
| ECMAScript Latest Draft (ECMA-262) The definition of 'Debugger statement' in that specification. | Living Standard | |
| ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'Debugger statement' in that specification. | Standard | |
| ECMAScript 5.1 (ECMA-262) The definition of 'Debugger statement' in that specification. | Standard | Initial definition |
| ECMAScript 3rd Edition (ECMA-262) The definition of 'Debugger statement' in that specification. | Standard | |
| ECMAScript 1st Edition (ECMA-262) The definition of 'Debugger statement' in that specification. | Standard | Only mentioned as reserved word. |
| Feature | Chrome | Edge | Firefox | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|---|
| Basic support | Yes | Yes | Yes | Yes | Yes | Yes |
| Feature | Android webview | Chrome for Android | Edge mobile | Firefox for Android | IE mobile | Opera Android | iOS Safari |
|---|---|---|---|---|---|---|---|
| Basic support | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
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https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/debugger