The catch clause of try statements used to require a binding:

try {
  doSomethingThatMightThrow();
} catch (exception) {
  //     ^^^^^^^^^
  // We must name the binding, even if we don’t use it!
  handleException();
}

In ES2019, catch can now be used without a binding. This is useful if you don’t have a need for the exception object in the code that handles the exception.

try {
  doSomethingThatMightThrow();
} catch { // → No binding!
  handleException();
}

Optional catch binding support #

• Chrome: 自 66 版本开始支持
• Firefox: 自 58 版本开始支持
• Safari: 支持
• Node.js: 自 8 版本开始支持
• Babel: 支持