使用 JQuery 根据 HTML 输入值生成多个块

Question

I want to generate a number of blocks using JQuery. I try this code:

$(function() {

            var input = $('<select name="contracts" id="contracts">\
                                <option value="default">-- Choose --</option>\
                                <option value="service">service</option>\
                                <option value="supply">supply</option>\
                                <option value="work">work</option>\
                            </select>\
                            <div>\
                                <label>start date</label>\
                                <input type="date" name="sdate" id="sdate">\
                            </div>\
                            <div>\
                                <label>end date</label>\
                                <input type="date" name="edate" id="edate">\
                            </div>');
            var newFields = $('');

            $('#nbr').bind('blur keyup change', function() {
                var n = this.value;
                if (n+1) {
                    if (n > newFields.length) {
                        addFields(n);
                    } else {
                        removeFields(n);
                    }
                }
            });

            function addFields(n) {
                for (i = newFields.length; i < n; i++) {
                    var newInput = input.clone();
                    newFields = newFields.add(newInput);
                    newInput.appendTo('#myForm');
                }
            }

            function removeFields(n) {
                var removeField = newFields.slice(n).remove();
                newFields = newFields.not(removeField);
            }
        });

But It doesn't work correctly. This is my HTML code:

<label>Number Of Contracts</label>
    <input type="number" name="nbr" id="nbr">
    <form method="post">
        <div id="myForm"></div>
        <input type="submit" name="submit" value="Submit">
    </form>

First It shows the number of divs I want but when I click anywhere it gives me the image below this is the image

Answer 1

try the one below, I have added a wrapper div and in the input variable and added a parseInt because n is evaluated as string.

        $(function() {

        var input = $('<div><select name="contracts" id="contracts">\
                            <option value="default">-- Choose --</option>\
                            <option value="service">service</option>\
                            <option value="supply">supply</option>\
                            <option value="work">work</option>\
                        </select>\
                        <div>\
                            <label>start date</label>\
                            <input type="date" name="sdate" id="sdate">\
                        </div>\
                        <div>\
                            <label>end date</label>\
                            <input type="date" name="edate" id="edate">\
                        </div></div>');
        var newFields = $('');

        $('#nbr').bind('blur keyup change', function() {
            var n = parseInt(this.value);
            if(isNaN(n)) {
                n = 0;
            }
            if (n > newFields.length) {
                addFields(n);
            } else {
                removeFields(n);
            }
        
            
        });

        function addFields(n) {
            for (i = newFields.length; i < n; i++) {
                var newInput = input.clone();
                newFields = newFields.add(newInput);
                newInput.appendTo('#myForm');

            }
        }

        function removeFields(n) {
            var removeField = newFields.slice(n).remove();
            newFields = newFields.not(removeField);
        }
    });