Outputs a warning message to the Web Console.
Note: This feature is available in Web Workers.
Note: In Chrome and Firefox, warnings have a small exclamation point icon next to them in the Web Console log.
Syntax
console.warn(obj1 [, obj2, ..., objN]); console.warn(msg [, subst1, ..., substN]);
Parameters
obj1...objN- A list of JavaScript objects to output. The string representations of each of these objects are appended together in the order listed and output.
msg- A JavaScript string containing zero or more substitution strings.
subst1...substN- JavaScript objects with which to replace substitution strings within
msg. This gives you additional control over the format of the output.
See Outputting text to the console in the documentation of console for details.
Specifications
| Specification | Status | Comment |
|---|---|---|
| Console API The definition of 'console.warn()' in that specification. |
Living Standard | Initial definition |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
| Desktop | Mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
warn | Chrome Full support Yes | Edge Full support 12 | Firefox Full support 4 | IE Full support 8 | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support 4 | Opera Android ? | Safari iOS ? | Samsung Internet Android Full support Yes |
| Substitution strings | Chrome Full support Yes | Edge
Full support
12
| Firefox Full support 9 | IE
Full support
10
| Opera ? | Safari ? | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support 9 | Opera Android ? | Safari iOS ? | Samsung Internet Android Full support Yes |
Legend
- Full support
- Full support
- Compatibility unknown
- Compatibility unknown
- See implementation notes.
- See implementation notes.
