CODEWITHSUNDEEP
javascriptfunction
Devilution
Devilution

Reputation: 13

Function returns nothing (not even undefined)

 var hi = function(type) {
    if (type == "boss") {
        return function(name) {
            alert("Hi chief " + name);
        };
    } else {
        return function(name) {
            alert("Hi " + name);
        };
    }
};

hi("boss"); // this will do nothing

var returnedFunction = hi();

returnedFunction("boss"); // prompt "Hi boss"

returnedFunction = hi("boss");

returnedFunction(); // prompt "Hi chief undefined"

returnedFunction("Douglas"); // prompt "Hi chief Douglas";

Ok so I understand pretty much everything that's going on except the first one:

hi("boss"); // this will do nothing

I would expect it to return "Hi chief undefined".

Doesn't the "boss" argument would mean it enters the if statement, where it should execute the function with argument name being undefined: hence you should get "Hi chief undefined".

Any information on how/why I get this behaviour would be most welcome. I am trying to understand and learn the basics of javascript !

Kind regards

Upvotes: 0

Views: 83

Answers (4)

LI_CH
LI_CH

Reputation: 1

`

var hi = function(type) {
    if (type == "boss") {
        return function(name) {
            alert("Hi chief " + name);
        };
    } else {
        return function(name) {
            alert("Hi " + name);
        };
    }
};


//return a function not excecuted
// hi();

// x is the returned function
var x = hi("boss");
x("name");

// 2 
// hi("boss")("name");

`

Upvotes: -1

Prosen Ghosh
Prosen Ghosh

Reputation: 655

hi("boss"); This line of code will return 

function (name) {
     alert("Hi chief " + name);
 }

this function.

Now you have to execute it.

in order to execute it just write hi("boss")();

Upvotes: 1

user13377331
user13377331

Reputation: 56

It returns only function, it doesn't execute it. You would have to write:

hi("boss")(); // it would print Hi chief undefined

in order to execute it

You could probably say that

hi("boss");

is equaivelnt of writing

function(name) {
  alert("Hi chief " + name);
};

While writing 

hi("boss")();

is like wiring

function(name) {
  alert("Hi chief " + name);
}(); // notiice the ()

Upvotes: 3

RomkaLTU
RomkaLTU

Reputation: 4129

Why not just:

var hi = function(type, name) {
    if (type == "boss") {
        alert("Hi chief " + name);
    } else {
        alert("Hi " + name);
    }
};

Upvotes: 0

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