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JavaScript

Posted by jason chan
jason chan
31,009 Points

var functionName = function() {} vs function functionName() {} ?

What's the difference between these two for defining a function and which is better?

var functionOne = function() {
    // Some code
};

function functionTwo() {
    // Some code
}

3 Answers

Jason Berteotti
Jason Berteotti
12,352 Points
Jason Berteotti
Jason Berteotti
12,352 Points

The first is declared as a variable, the second is declared as a function. In general, they behave the same. The difference is that JavaScript prepares functions declarations before processing the rest of the code; thus, the second function is available asynchronously, and the function declared as a variable is available only after it is declared.

Dan Gabriel Valeriu Voineag
Dan Gabriel Valeriu Voineag
3,797 Points
Dan Gabriel Valeriu Voineag
Dan Gabriel Valeriu Voineag
3,797 Points

The first one is storing the function inside a variable and the function is called with a empty argument and called anonymous. The second piece of code is a function.

Bappy Golder
Bappy Golder
13,449 Points
Bappy Golder
Bappy Golder
13,449 Points

Thanks Dan, you've got a better explanation there.