In JavaScript, the try...catch statement is used to handle errors that may occur during the execution of a block of code. The try block contains the code that may throw an exception, and the catch block contains the code that will be executed if an exception is thrown. Here's an example:

try {
  // code that may throw an exception
  doSomething();
} catch (error) {
  // code to be executed if an exception is thrown
  console.error(error);
}

In this example, if the doSomething() function throws an exception, the code in the catch block will be executed and the error will be logged to the console. If no exception is thrown, the catch block will be skipped.

You can also use the finally block to specify code that should be executed regardless of whether an exception is thrown or not. The finally block will be executed after the try block and any matching catch block:

try {
  // code that may throw an exception
  doSomething();
} catch (error) {
  // code to be executed if an exception is thrown
  console.error(error);
} finally {
  // code to be executed regardless of whether an exception is thrown
  cleanup();
}

In this example, the cleanup() function will be called regardless of whether an exception is thrown or not.