CODEWITHSUNDEEP
javascriptfunctionexpressiondeclaration
Bail3y
Bail3y

Reputation: 51

Is a function declaration (statement) also a function expression technically?

The simple definition of an expression is "something that resolves to a value." The simple definition of a statement is "an executable chunk of code."

With that in mind, since this function below resolves to a value of 6, does that make it an expression as well, instead of a statement, or both? 

function ii () {
return 6;
}
ii();

Upvotes: 1

Views: 60

Answers (2)

imaxwill
imaxwill

Reputation: 113

By your own references, no. The function itself does not resolve to anything, it just returns an already-resolved value. It's only a statement.

You are defining the function. That makes it a statement. Yes, you could say that calling the function "Resolves" it to the output, but it only triggers the output.

A value is more like an expression. It's not executable, it just is.

A getter is both an expression and a statement rolled into one:

Object.defineProperty(window, "ii", { get: function () { return 6 }});
// Returns '6'
ii;

ii = 7; 
// Logs '6' because setting 'ii' does not change the resolution function.
console.log(ii);

Upvotes: 1

slevy1
slevy1

Reputation: 3832

A function declaration defines what a function should do, as follows:

function ii () {
  return 6;
}

When that function is invoked as below, it becomes a function expression:

if ( ii() ) {
    console.log("true"); 
}
else
{
   console.log("false");
}

You can also have a function expression based on a declaration, as follows:

(function iii () {
  console.log(3);
  }()
 )

The following represents another kind of expression, for the value of a is the indicated function declaration:

var a = function iv() {
    return 5;
}

An interesting read on this topic is here.

Upvotes: 2

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