Javascript understanding

This is probably a stupidly basic question for this community, but if someone could explain it to me I would be very great full, I am so confused by it. I found this tutorial on the net and this was example.

<script type="text/javascript">
   开发者_高级运维 function sports (x){
        alert("I love " + x);
    }
    sports ("Football");
    sports ("Rally");
    sports ("Rugby");
</script>

Why does this display the 3 variables: Football, Rally and Rugby?

Is it because x = sports? So when the variables of sports are defined they get displayed?

I think I confused myself more when writing this so I hope it kind of makes sense :(

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Unless I'm missing something, the reason it shows all three variables (sequentially, not simultaneously) is because you're calling the function three times, each time you call it you're passing a variable ("Football" for example), which the function uses internally to complete the alerted message.

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You're defining a function, called "sports", that takes one argument, named "x". Each time you call the function, it alerts a message, substituting the argument you pass in for "x". In this example, you call the function three times, with three different values of "x".

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I hope this helps you, x is a container for a value. So when you say something like sports ("Football"); it behaves as if this:

alert("I love " + x);

was actually this:

alert("I love " + "Football");

This is because x contains "Football".

Think of it as a placeholder for a value of some kind.

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Every time you write sports("text") you call a function. It means that it is executed.

Your function is displaying an alert message using an argument. In your case you execute your function three times with 3 different arguments.