How can i check true errors?

[sbslord]

i have a callback function

function(err, result){
    if(err) console.log(this.name + ' mysql callback error: '+err);
}

True error here is a object: who say me table database.user is not exist
but this is a object error and my if is be false so i dont watch the error.
but without if only console.log(err) i see the true error.
how need use? if(typeof err === 'object' || typeof err !== 'undefined') ?

[dougwilson]

This is a JavaScript language question. The short answer is you only need to do if (err), because err will always be a truthy-value if there is an error and a falsy-value if there is no error.

[sbslord]

but not run my console.log and haver error, err is a object and not be true so not enough simple if(err)

[dougwilson]

All objects in JavaScript are true. There is no object that would be false.

[sbslord]

ahh i found the problem when i use console.log(this.name + ' mysql callback error: '+err);
here this.name in my code was my_function.name and i wrote bad my_function and dont get error on console

[sbslord]

What better res.send(mysql_error) or console.log(mysql_error) ?
because if have a mysql error the user dont see what the problem and click again and again and be angry

[dougwilson]

If you are using Express, you should be doing next(err) and letting Express handle the error flow for you.