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JavaScript

Posted by Niem Nguyen
Niem Nguyen
2,502 Points

How do I show my result (from scripts) on a <li> on my webpage?

This is my HTML 

<body>
        <div class="container">
            <h1>Ping Pong</h1>
            <form id="pongTable">
                <div class="form-group">
                    <label for="pingPong">Enter number to start game: </label>
                    <input id="userInput" type="number">
                </div>

                <button type="submit" class="btn btn-success">Play!</button>
            </form>

            <div>
                <ul class="result"></ul>

            </div>
        </div>  
    </body>

Here is the logic

//BUSINESS LOGIC
var pingPong = function(userInput) {
    for (var i = 1; i < userInput; i++) {
        if ((i % 3 === 0) && (i % 5 ===0)){
            document.write("ping pong");
        } else if (i % 5 === 0) {
            document.write("ping");
        } else if (i % 3 === 0) {
            document.write("pong"); 
        } else {
            document.write(i);      
        }
    }
}

//UI LOGIC

$(function() {
    $("#pongTable").submit(function(event) {
        event.preventDefault();

        var userInput = parseInt($("#userInput").val());
        var result = pingPong(userInput);
        $(".result").text(result);
    });
});

This is what I get when I enter a number like 15: 12pong4pingpong78pongping11pong1314

I would like it to look like a list of list items instead of this one giant run-on.

Sean T. Unwin
Sean T. Unwin
28,690 Points
Sean T. Unwin
Sean T. Unwin
28,690 Points

I edited your post for code formatting.

2 Answers

Sean T. Unwin
Sean T. Unwin
28,690 Points
Sean T. Unwin
Sean T. Unwin
28,690 Points

This is the way I completed the task. I have commented the changes that have been made, but if you have questions feel free to ask. :)

//BUSINESS LOGIC

// Create a list item as a string and return it
// Takes 1 argument which is the content to display in the list item
function createLi(content) {
    // opening list item tag
    var openLi = '<li>';
    // closing list item tag with line ending
    var closeLi = '</li>\n';

    // return the content enclosed in a list item
    return openLi + content + closeLi;
}

var pingPong = function(userInput) {
    // String to hold all the list items
    var str = '';

    for (var i = 1; i < userInput; i++) {
        if ((i % 3 === 0) && (i % 5 ===0)){
            // Create list item with message
            // Add list item to string
            str += createLi("ping pong");
        } else if (i % 5 === 0) {
            // Create list item with message
            // Add list item to string
            str += createLi("ping");
        } else if (i % 3 === 0) {
            // Create list item with message
            // Add list item to string          
            str += createLi("pong"); 
        } else {
            // Create list item with message
            // Add list item to string          
            str += createLi(i);      
        }
    }

    // Return the string
    return str;
}

//UI LOGIC

$(function() {

    $("#pongTable").submit(function(event) {
        event.preventDefault();

        var userInput = parseInt($("#userInput").val());
        var result = pingPong(userInput);
        // Changed .text() to .html() for rendering the li tags
        $(".result").html(result);
    });
});

All that is left to do is to style the list. :-D

Niem Nguyen
Niem Nguyen
2,502 Points

Thank you! It looks very comprehensive. Much appreciated =)

Arjuna Huffman
Arjuna Huffman
2,400 Points
Arjuna Huffman
Arjuna Huffman
2,400 Points

If you want to append list items to an unordered list, you can do that like this:

//HTML markup

<ul id="some-list"></ul>

//JavaScript

var names = ['Bill', 'Selma', 'Henry the fifth']; var someList = document.getElementById('some-list');

function addToList(list, arr) {

     /* We append the list items to a document fragment first so as to minimize the amount of work we do on the DOM.
          A document fragment is like a virtual dom node that you can append items too and then, to insert the new             markup into the DOM, you simply append the document fragment to it. */

     var fragment = document.createDocumentFragment();

     for (var i = 0; i < arr.length; i++) {

          //Create the list item

         var listItem = document.createElement('li');

               //Set the text content of the list item

         listItem.textContent = arr[i];

         //Append the list item to the document fragment

         fragment.appendChild(listItem);
     }

     //When the loop is over, append the document fragment to the dom.

     list.appendChild(fragment);

}

addToList(someList, names);

Niem Nguyen
Niem Nguyen
2,502 Points

Thanks for the tips. I will test it out!