Cannot read property map of undefined error in console when you delete an item

Cannot read property map of undefined error in console when you delete an item
0.0 0

#1
<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <link href="https://fonts.googleapis.com/css?family=Open+Sans:100,300,400,600" rel="stylesheet" type="text/css">
        <link href="http://code.ionicframework.com/ionicons/2.0.1/css/ionicons.min.css" rel="stylesheet" type="text/css">
        <link type="text/css" rel="stylesheet" href="style.css">
        <title>Budgety</title>
    </head>
    <body>
        
        <div class="top">
            <div class="budget">
                <div class="budget__title">
                    Available Budget in <span class="budget__title--month">%Month%</span>:
                </div>
                
                <div class="budget__value">+ 2,345.64</div>
                
                <div class="budget__income clearfix">
                    <div class="budget__income--text">Income</div>
                    <div class="right">
                        <div class="budget__income--value">+ 4,300.00</div>
                        <div class="budget__income--percentage">&nbsp;</div>
                    </div>
                </div>
                
                <div class="budget__expenses clearfix">
                    <div class="budget__expenses--text">Expenses</div>
                    <div class="right clearfix">
                        <div class="budget__expenses--value">- 1,954.36</div>
                        <div class="budget__expenses--percentage">45%</div>
                    </div>
                </div>
            </div>
        </div>
        
        
        
        <div class="bottom">
            <div class="add">
                <div class="add__container">
                    <select class="add__type">
                        <option value="inc" selected>+</option>
                        <option value="exp">-</option>
                    </select>
                    <input type="text" class="add__description" placeholder="Add description">
                    <input type="number" class="add__value" placeholder="Value">
                    <button class="add__btn"><i class="ion-ios-checkmark-outline"></i></button>
                </div>
            </div>
            
            <div class="container clearfix">
                <div class="income">
                    <h2 class="icome__title">Income</h2>
                    
                    <div class="income__list">
                       
                        <!--
                        <div class="item clearfix" id="income-0">
                            <div class="item__description">Salary</div>
                            <div class="right clearfix">
                                <div class="item__value">+ 2,100.00</div>
                                <div class="item__delete">
                                    <button class="item__delete--btn"><i class="ion-ios-close-outline"></i></button>
                                </div>
                            </div>
                        </div>
                        
                        <div class="item clearfix" id="income-1">
                            <div class="item__description">Sold car</div>
                            <div class="right clearfix">
                                <div class="item__value">+ 1,500.00</div>
                                <div class="item__delete">
                                    <button class="item__delete--btn"><i class="ion-ios-close-outline"></i></button>
                                </div>
                            </div>
                        </div>
                        -->
                        
                    </div>
                </div>
                
                
                
                <div class="expenses">
                    <h2 class="expenses__title">Expenses</h2>
                    
                    <div class="expenses__list">
                       
                        <!--
                        <div class="item clearfix" id="expense-0">
                            <div class="item__description">Apartment rent</div>
                            <div class="right clearfix">
                                <div class="item__value">- 900.00</div>
                                <div class="item__percentage">21%</div>
                                <div class="item__delete">
                                    <button class="item__delete--btn"><i class="ion-ios-close-outline"></i></button>
                                </div>
                            </div>
                        </div>

                        <div class="item clearfix" id="expense-1">
                            <div class="item__description">Grocery shopping</div>
                            <div class="right clearfix">
                                <div class="item__value">- 435.28</div>
                                <div class="item__percentage">10%</div>
                                <div class="item__delete">
                                    <button class="item__delete--btn"><i class="ion-ios-close-outline"></i></button>
                                </div>
                            </div>
                        </div>
                        -->
                        
                    </div>
                </div>
            </div>
            
            
        </div>
        
        <script src="app.js"></script>
    </body>
</html>


// here is javascript course

#2

You provided your html, but no JavaScript. Also, you will need to explain what you expect your code to do vs what it is doing. Be as detailed as you can, so we can focus on the problem part of your code. Do you have a codepen or jsfiddle version of your project?