NodeJS TypeError Callback is not a function
11,134
fun2 expects to get a function. what you gave is the result (which is 'undefined') of func1. meaning
var something = fun1(log);
fun2(something);
So not sure what you expect to do in fun2 but you need to provide a callback and not undefined.
you could do:
function fun1(callback){
var result = "result of function 1";
callback(result)
return callback
};
function fun2(callback){
var result = "result of function 2";
callback(result)
};
fun1(log); // displays "result of function 1"
fun2(log); // displays "result of function 2"
fun2(fun1(log));
Author by
Christian68
Updated on June 05, 2022Comments
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Christian68 about 2 years
I have the following piece of code:
function fun1(callback){ var result = "result of function 1"; callback(result) }; function fun2(callback){ var result = "result of function 2"; callback(result) }; fun1(log); // displays "result of function 1" fun2(log); // displays "result of function 2" fun2(fun1(log)); // Type Error ...
Where log is simple function (i.e. console.log(data)...) I'm wondering why fun2(fun1(log)) does not display "result of function 1" as one would expect. What is missing? Many thanks - Christian
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Christian68 over 7 yearsThanks Sagie for your quick response. Is this the standard way of doing when you want to chain functions together?
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sagie over 7 yearsthere are many ways to chain functions, for example to return a function, to use promise and so on... there is no 1 specific standard way.