cannot pass array in a function javascript

Question

I'm learning javascript and I want to fill an array in one function and pass it as a parameter in the second function. I have the following code but for some reason it is not working.

function gameplay(tmp) {
    for (var i = 0; i < tmp.length; i++) {
        if (xTrans >= tmp[0] - 1
            && xTrans < tmp[0]
            && zTrans <= tmp[1] - 1
            && zTrans > tmp[1])
        {
            //some code here
        }
    }
}

function fillMap() {
    var bounds = new Array();
    for (var y = 0; y < map.length; y++) {
        for (var x = 0; x < map[0].length; x++) {
            if (map[y][x] == '1') {
                bounds[length] = 4 * x;
                length++;
                bounds[length] = -y - 4 * y;
                length++;
            }
        }
    }
    return bounds;
}

and I call like this:

var tmp = fillMap();
gameplay(tmp);

Thanks in advance..

Are you getting some kind of error message, or is the output/result simply not what you expect? — Brian Driscoll
– Brian Driscoll, Commented May 15, 2014 at 17:12
Make sure your code runs at all. The length variable is not defined. I assume you want bounds.push(...) instead. If you are new to arrays in JS, I recommend to a tutorial: developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/… . — Felix Kling
– Felix Kling, Commented May 15, 2014 at 17:13
length is defined and the message i get when im trying to print the array is that it is empty. — user3478067
– user3478067, Commented May 15, 2014 at 17:17
In for(var y=0; y<map.length ;y++), map ss global variable? Is It initiate with what value? — Samuel
– Samuel, Commented May 15, 2014 at 17:20

cwallenpoole · Accepted Answer · 2014-05-15 17:25:11Z

1

You might want to try this just to confirm what happens when you have a clear and obvious input:

function fillMap() {
var map = [[0]];

That should give you the output of: [4, -5]

Some potential issues

map isn't defined anywhere
length isn't defined anywhere
xTrans is not defined anywhere
zTrans is not defined anywhere
It seems unlikely, based on what I see, that the if condition can be met:

xTrans >= tmp[0]-1 && xTrans < tmp[0] // translates to if xTrans == tmp[0] - 1

Some other thoughts

You're better off using bounds.push instead of bounds[length] = $val
for(var y=0; y<map.length ;y++) { for(var x=0; x<map[0].length ;x++) { would be safer/faster as var yLen = map.length; var xLen = map[0].length; for(var y=0; y<yLen ;y++) { for(var x=0; x<xLen ;x++) {
bounds[length] = -y - 4 * y is the same as bounds[length] = -5 * y;

edited May 15, 2014 at 17:25

answered May 15, 2014 at 17:19

cwallenpoole

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1 Comment

user3478067 Over a year ago

I tried push and the for statement as you said and the other variables are defined but still the same problem

KaranHP · Accepted Answer · 2014-05-15 17:24:27Z

0

From you comment it seems that array is not being filled as you have some condition to fill array . So first check you condition is being full filled or not.

answered May 15, 2014 at 17:24

KaranHP

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