javascript - Node async and exception handling -

i'm using async waterfall. when 1 of functions calls callback(err), custom async callback called. inside of there throw error, hoping caught in try block around async, that's not happening.

try {     async.waterfall([function1, function2], myasynccallback); } catch(err) {     console.log("this code never executed."); }  var function1 = function() { ...    //some error occurs:    callback(new error(errmsg), errmsg); ... }  var function2 = function() { ... }  function myasynccallback(err, result) {     console.log("this code gets executed.");     if (err) {             console.log("this code gets executed too.");             throw new error("i want error caught @ top around catch around async.waterfall()");         } } 

https://runkit.com/imjosh/async-try-catch/2.0.0

var async = require('async');  try {   async.waterfall([function1, function2], myasynccallback); } catch(err) {   errorhandler(err); }  function function1(callback) {   console.log('in fn1')      callback(null,'fn1');    }  function function2(fn1, callback) {   console.log('in fn2')   callback(null, fn1 + 'fn2'); }  function myasynccallback(err, result) {     if (err) {       console.error('there error: ' + err);       return;     }     //an error occurs. gets caught outer try block     //var foo = outer; //oops, outer not defined. throws error      //same scenario inside async function     //can't/won't caught outer try block     settimeout(function(){          try{ //need try here           var foo = inner; //oops, inner not defined. throws error         }          catch(err) {           errorhandler(err);        }     }, 1000);      console.log('result was: ' + result); }  function errorhandler(err){    //make error handler function can called either catch   console.log('caught error: ' + err); }