try

In JavaScript, the try keyword starts a statement that runs a block of code and handles any exception the block throws. The block must be followed by a catch clause, a finally clause, or both, and all three parts must be blocks in braces.

When a statement in the try block, or a function it calls, throws, the rest of the block is skipped and control moves to catch. If nothing throws, catch is skipped. The finally block runs in both cases. Exceptions come from runtime errors and from the throw statement. An exception that an inner try statement doesn’t catch moves on to the nearest enclosing one.

A try block catches a rejected promise only when code inside it waits for the promise with await. A callback that runs later, such as one passed to setTimeout(), runs outside the try block.

try {
  <statements>
} catch [(<binding>)] {
  <statements>
} [finally {
  <statements>
}]

try {
  <statements>
} finally {
  <statements>
}

> function parseSettings(text) {
…   try {
…     return JSON.parse(text);
…   } catch (error) {
…     console.log(`Invalid settings: ${error.message}`);
…     return {};
…   }
… }
undefined

> parseSettings('{"theme": "dark"}')
{ theme: 'dark' }

> parseSettings("")
Invalid settings: Unexpected end of JSON input
{}