The class
keyword can be used to define a class inside an expression.
You can also define classes using the class
declaration.
The class
keyword can be used to define a class inside an expression.
You can also define classes using the class
declaration.
Note: An expression statement cannot begin with the keyword class
to avoid ambiguity with a class
declaration. The class
keyword only begins an expression when it appears in a context that cannot accept statements.
A class
expression is very similar to, and has almost the same syntax as, a class
declaration. As with class
declarations, the body of a class
expression is executed in strict mode. The main difference between a class
expression and a class
declaration is the class name, which can be omitted in class
expressions to create anonymous classes. Class expressions allow you to redefine classes, while redeclaring a class using class
declarations throws a SyntaxError
. See also the chapter about classes for more information.
If you want to refer to the current class inside the class body, you can create a named class expression. The name is only visible within the scope of the class expression itself.
Desktop | Mobile | Server | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Opera | Safari | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | WebView Android | Deno | Node.js | ||
class |
42 | 13 | 45 | 29 | 7 | 42 | 45 | 29 | 7 | 4.0 | 42 | 1.0 | 6.0.0 |
© 2005–2023 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/class