How do I assign a function to the property of a Javascript object?

Question

I was looking and struggling to the following example:

var player1= {name: "Chris", score: 1000, rank: 1};
var player2= {name: "Kristofer", score: 100000, rank: 2};

function playerDetails(){
alert("The name of the player is "+ this.name + "."+ " His score is : "+ this.score + "and his rank : "+ this.rank);
}
player1.logDetails= playerDetails;
player2.logDetails= playerDetails;

player1.logDetails();
player2.logDetails();

As far as I know player1.logDetails is a property of player1 or a method of player1. So I can't understand how the author assigns a property to a function. Also I don't get why you would write it like that instead of : player1.logDetails= playerDetails(); which I have tried and doesn't work.

Then he calls player1.logDetails() which is a function but not declared anywhere.(?)

If anyone could help?? Thank you in advance

Answer 1

If the code was written like this, I bet you understand it:

var player1 = {
                name: "Chris", 
                score: 1000, 
                rank: 1,
                playerDetails: function() { alert('The name is '+ this.name) }
};

var player2 = {
                name: "Kristofer", 
                score: 10000, 
                rank: 2,
                playerDetails: function() { alert('The name is '+ this.name) }
};

The author of the code wanted to define the "playerDetails()" function once.

Another way of showing this in a simplified manner is:

var player1 = {
                name: "Chris", 
                score: 1000, 
                rank: 1
};

player1.playerDetails=function() { alert('The name is '+ this.name) }

var player2 = {
                name: "Kristofer", 
                score: 10000, 
                rank: 2
};

player2.playerDetails=function() { alert('The name is '+ this.name) }

So if you wanted to optimize the code above by only writing the playerDetails function once, it would look like the code in your post.

If I had written the code block, I might have written it like this: (which is easy to read)

function playerDetailsFunc() {alert('The name is '+ this.name) }

var player1 = {
                name: "Chris", 
                score: 1000, 
                rank: 1,
                playerDetails: playerDetailsFunc
};

var player2 = {
                name: "Kristofer", 
                score: 10000, 
                rank: 2,
                playerDetails: playerDetailsFunc
};

Answer 2

Javascript functions are no different from other values or objects.
You can assign them to whatever you want; you can even pass them as parameters.