Javascript program help
Update this program is supposed to keep track of the number of times each side is rolled not each roll itself.
I am working on a javascript exercise that needs to take two dice, roll them 1000 times and keep track of each roll. I thought the best way to do it was to use an array but I am not exactly sure if I am going in the right direction with what I am doing. I just need a little help in pointing me in the right direction to get this to work because right now it doesnt output anything. Thanks here is my code:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Exercise Five</title>
<script type="text/javascript">
function Die(){
this.roll = function(){
this.sides = 0;
return parseInt((Math.random( ) * 1000) % this.sides) + 1;
}
}
</script>
</head>
<body>
<script type="text/javascript">
var dieOne = new Die();
var dieTwo = new Die();
var rollOne = 0;
var rollTwo = 0;
var roll_value = new Array();
var arrayPlace = 0;
for开发者_StackOverflow社区(var i = 0; i < 1000 ; i++){
rollOne = dieOne.roll();
dieOne.sides = 10;
rollTwo = dieTwo.roll();
dieTwo.sides = 10;
arrayPlace = (rollOne + rollTwo) - 2;
roll_value[arrayPlace]++;
}
for( var i = 0; i < roll_value.length; i++){
document.writeln(roll_value[i]);
}
</script>
</body>
</html>
Sorry, see updated code below:
var dieOne = new Die();
var dieTwo = new Die();
var rollOne = 0;
var rollTwo = 0;
var roll_values = new Array();
for(var i = 0; i < 1000 ; i++){
rollOne = dieOne.roll();
rollTwo = dieTwo.roll();
roll_values[i] = { 'first': rollOne,
'second': rollTwo,
'value': 0 };
// 1. iterate through past roll_values[i].first, roll_values[i].second
// in order to determine what you need to increment and by how much
// 2. finally set roll_values[i].value = var_containing_value;
}
for( var i = 0; i < roll_value.length; i++){
console.log(roll_value[i]);
}
And, another note, for debugging, console.log(whatever) is excellent and supported on most modern browsers (IE > 8, thanks Kolink). The console log will show up in the javascript/error console.
There were two problems: how you were storing the roll values and how you were incrementing your array. Both should now be fixed.
Try this:
function Dice(sides) {
this.sides = sides;
}
Dice.prototype.roll = function() {
return (Math.random() * (this.sides + 1)) | 0 ;
}
var counts = [];
var d1 = new Dice(6);
var d2 = new Dice(6);
var s;
for (var i=1000; i; i--) {
s = d1.roll() + d2.roll();
counts[s] = typeof counts[s] == 'undefined'? 1 : ++counts[s];
}
// Show results
for (var i=0, iLen=counts.length; i<iLen; i++) {
console.log(i + ' : ' + counts[i]);
}
加载中,请稍侯......
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