Question

从下面的代码我尝试从数组中删除数据。不幸的是它没有从我的数组中删除数据，ary，看看你是否可以帮我解决这个问题

var ary = [{"Force":"Force Converter"},{"Power":"Power Converter"}];

 function removeFav(n,v){ 
       var index = ary.indexOf(n);
       alert(index);
       if (index > -1) {
           ary.splice(index, 1);
        }
         alert("New updated Array:"+ary);
   }

要求删除

removeFav("Power","Power Converter");  // this calls the above method

Answer 1

注意：对indexOf的浏览器支持是有限的，IE7-8不支持。

以下是演示Demo，您可以在下面找到该代码。

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title></title>
    <script src="//cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
    <script>

        localStorage.clear();

        var ary = [];
        ary.push({ "Force": "Force Converter" })
        ary.push({ "Power": "Power Converter" });

        function contains(arr, k) {
            var doesContain = false;
            for (var i = 0, length = arr.length; i < length; i++) {
                var item = arr[i];
                if (item.hasOwnProperty(k)) {
                    doesContain = true;
                    break;
                }
            }
            return doesContain;
        }

        if (localStorage.getItem("testObject") != null) {
            alert("localstorage has item testobject");
            //Parse the retrieved value into an array
            ary = JSON.parse(localStorage.getItem('testObject'));
        }

        function setFavorite(k, v) {

            var obj = {};
            obj[k] = v;

            var hasItem = contains(ary, k);

            if (!hasItem) {
                ary.push(obj);
                // Put the object into storage
                localStorage.setItem('testObject', JSON.stringify(ary));
            }


            // Retrieve the object from storage
            var retrievedObject = localStorage.getItem('testObject');

            // Parse the retrieved value into an array
            var retrievedArray = JSON.parse(retrievedObject);

            // clear the ouput first
            $("#fab-id").html("");
            //iterate over the array which contains key-value pairs
            for (var i = 0; i < retrievedArray.length; i++) {
                var item = retrievedArray[i];

                var key = Object.keys(item)[0];
                var value = item[key];

                //----------BELOW CODE DOES NOT WORK PROPERLY----   
                $("#fab-id").append('<a>' + value + '</a><br/>');

            }
        }

    </script>
</head>
<body>
    <button id="btn">Click me!</button>
    <button id="btn2">Add another item!</button>

    <div id="fab-id"></div>

    <script>
        //adding a simple click event handler
        document.getElementById("btn").addEventListener("click", function () {
            //setFavorite("Power", "Power Converter");
            //setFavorite("Power", "Power Converter");
            setFavorite("propA", "X");
        });

        document.getElementById("btn2").addEventListener("click", function () {
            //setFavorite("Power", "Power Converter");
            //setFavorite("Power", "Power Converter");
            setFavorite("xyz", "blabal");
        });
    </script>

</body>
</html>

Answer 2

您的包含功能非常完美。这应该适合您，只需将名称直接用作属性

function setFavorite(name, value){
 alert(contains(ary, value));

    var obj = {}; 
    obj.name = value; 
    alert(obj.name);
    ary.push(obj);
    alert(contains(ary, obj));

Answer 3

您的代码实际上是在调用ary.indexOf("Power")。但是ary中没有索引为Power的元素，因此调用总是失败的原因。实际上，Array.indexOf()不适用于您的场景，因为它只适用于简单类型，而不适用于复杂对象。

您需要做的是检查该数组中具有指定键的对象，如果找到该对象，则删除该对象。为此，您使用Object.hasOwnProperty()方法：

function removeFav(key) { for (var i = 0; i < ary.length; i ++) { // if the current array item has a property // that matches the specified one, remove that item if (ary[i].hasOwnProperty(key)){ ary.splice(i, 1); return; } } }

javascript：如何从数组中删除数据

3 个答案: