Unable to understand why the try and catch is not working as expected in mongoose

First let’s take a look at a function that uses a synchronous usage pattern.

// Synchronous usage examplevar result = syncFn({ num: 1 });// do the next thing

When the function syncFn is executed the function executes in sequence until the functionreturns and you’re free to do the next thing. In reality, synchronous functions should bewrapped in a try/catch. For example the code above should be written like this:

// Synchronous usage examplevar result;try {  result = syncFn({ num: 1 });  // it worked  // do the next thing} catch (e) {  // it failed}

Now let’s take a look at an asynchronous function usage pattern.

// Asynchronous usage exampleasyncFn({ num: 1 }, function (err, result) {  if (err) {    // it failed    return;  }  // it worked  // do the next thing});

When we execute asyncFn we pass it two arguments. The first argument is the criteria to be used by the function. The second argument is a callback that will execute whenever asyncFn calls the callback. asyncFn will insert two arguments in the callback – err and result). Wecan use the two arguments to handle errors and do stuff with the result.

The distinction here is that with the asynchronous pattern we do the next thing within the callback of the asynchronous function. And really that’s it.