CODEWITHSUNDEEP
javascriptjquery
Johnroiste
Johnroiste

Reputation: 71

How can I choose a random value of each data attribute together to choose a random cell?

I have a dynamically created table and have given each cell row and column attributes to give them numbers between 0-9(10X10 table) called data-x, data-y. I want to select a random data-x, and data-y (that has a class of empty) and then assign that cell a another class. I know that I could do it in an easier way by randomly selecting just the cell itself but for some reason it needs to be done this way.

I made variables for random numbers between 0-9 but don't really know how they can connect to my data-x/y in order to do the above.

Could anyone give me advice on the simplest way to do this?

Thanks

$( document ).ready(function() {
    var body = document.getElementsByTagName("body")[0];
    var table = document.createElement('TABLE');
    var tblB = document.createElement('TBODY');
    table.appendChild(tblB);
    var num = [1];
   
    for (var i = 0; i <10; i++) {
        var tr = document.createElement('TR');
        tblB.appendChild(tr);
        $(tr).attr('data-x', i)

        for (var j=0; j<10; j++) {
            var td = document.createElement('TD');
            tr.appendChild(td);
            td.append(num++);
        $(td).attr('data-y', j);
        }
    }
    body.appendChild(table);

    var randomRow = Math.floor(Math.random() * 9);
        var randomCol = Math.floor(Math.random() * 9);
    //How to select a <td> of random data-x,data-y with these     randomRow and randomCol numbers
    //$(td).???
    console.log(randomCol, randomRow);

    //Give all cells a class of empty to start
    $("td").addClass('empty');
    var obs = 0;
    while (obs <= 10) {
        //Find random row and column that has class empty, add             Class(dimmed) to that random row and column (eg. 2 1)
        // var randomRow = Math.floor(Math.random() * 9);
        // var randomCol = Math.floor(Math.random() * 9);
        // console.log(randomNum + randomCol);
        obs++    
    }
})
table td {
    padding: 25px;
    border: 5px solid red;
}

table {
    margin: auto;
}

.dimmed {
    background: black;
}
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <link rel="stylesheet" href="style.css">
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>   
    <script src="script.js"></script>
</head>
<body bgcolor="lightblue">
    <center>
        <h1>Create table in a dynamic way using javascript</h1>
    </center>
    <CENTER>
        <div id=TBL></div>
    </CENTER>
</body>
</html>

Upvotes: 2

Views: 485

Answers (1)

iguypouf
iguypouf

Reputation: 770

If your x and y are always iterative from 0 to 9, you really dont need to add these attributes as your rows and cells are already indexed.

As you seem to use jquery, this simply works without any attributes :

var randomRow = Math.floor(Math.random() * 9);
var randomCol = Math.floor(Math.random() * 9);

$("#TBL tr:eq(" + randomRow + ") td:eq(" + randomCol + ")").removeClass("empty").addClass("newclass");

or for better performance in modern browsers

$("#TBL tr").eq(randomRow).children("td").eq(randomCol)

Having more info of what you want to achieve, I would better build an array :

var cells = array[];
while (cells.length < 10) {
    var cell = Math.random() * 99;
    if(!cells.includes(cell)) cells[] = cell;
}

cells.foreach(function(item) {
    $("#TBL td").eq(item).removeClass("empty").addClass("newclass");
});

You build a 10-len array with 10 unique cell number; then for each element of your array you tag the correspondant cell. Note the td selector instead of tr that will retrieves all your cells in a single collection.

Upvotes: 2

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