How can i add numbers to a variable in JS?

Question

I have been trying to do a simple game where you try to get the right number as the random number. If you win, you get 1 point. But I wasn't able to give that point. Here is what i have done :

<html>
<head>
    <title>Luck Game</title>
    <script>
    function onClick(){
        var number = Math.floor(Math.random()*10);
        var usernumber = document.getElementById("input").value ;
        var points = 0;
        document.getElementById("Answer").innerHTML = number ;
        document.getElementById("points").innerHTML = "Points in your account : " + points;
        if(usernumber == number){
            document.getElementById("WIN?").innerHTML = "You WON !. You got 1 point added to your account !";
points = points + 1;

        }
        else{
            document.getElementById("WIN?").innerHTML = "Ow, no luck, you lost..."
        }

    }
    </script>
</head>
<body>
    <input id="input"></input>
    <p id="Answer"></p>
    <button onClick="onClick()"></button>
    <p id="WIN?"></p>
    <p id="points"></p>
</body>

But the "points = points + 1" is not working ! what is wrong ? please help me .

you must ensure point is treated as a number, points = parseInt(points )+ 1; — davidkonrad
– davidkonrad, Commented Jul 7, 2014 at 12:43

Tuğrul · Accepted Answer · 2014-07-07 12:47:15Z

4

You should declare your var points outside click function. E.g :

<script>
var points = 0;
    function onClick(){
        var number = Math.floor(Math.random()*10);
        var usernumber = document.getElementById("input").value ;

        document.getElementById("Answer").innerHTML = number ;
        document.getElementById("points").innerHTML = "Points in your account : " + points;
        if(usernumber == number){
            document.getElementById("WIN?").innerHTML = "You WON !. You got 1 point added to your account !";
points = points + 1;

        }
        else{
            document.getElementById("WIN?").innerHTML = "Ow, no luck, you lost..."
        }

    }
    </script>

So the counter will be saved somewhere else without being resetted everytime function procs.

edited Jul 7, 2014 at 12:47

answered Jul 7, 2014 at 12:42

Tuğrul

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Comments

Erik Gillespie · Accepted Answer · 2014-07-07 12:44:41Z

The way you've written it, points is a variable local to the onClick() function so it will get reset to zero each time the function is called. If you pull the initialization of points out of onClick() then you will be able to safely increment its value:

<script>
    var points = 0;
    function onClick(){
        var number = Math.floor(Math.random()*10);
        var usernumber = document.getElementById("input").value ;

        document.getElementById("Answer").innerHTML = number ;
        document.getElementById("points").innerHTML = "Points in your account : " + points;
        if(usernumber == number){
            document.getElementById("WIN?").innerHTML = "You WON !. You got 1 point added to your account !";
            points++;
        } else {
            document.getElementById("WIN?").innerHTML = "Ow, no luck, you lost..."
        }
    }
</script>

Ashley Medway · Accepted Answer · 2014-07-07 13:37:41Z

1

Declare var points outside function:

var points = 0;

function onClick(){
    ...
}

edited Jul 7, 2014 at 13:37

Ashley Medway

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answered Jul 7, 2014 at 12:46

zucker

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