Javascript 用于在可观察数组中添加和替换项的函数
我正在尝试写一个函数,这个函数是1。将一个项目添加到可观察数组中,然后单击2。替换阵列中已存在的项Javascript 用于在可观察数组中添加和替换项的函数,javascript,knockout.js,Javascript,Knockout.js,我正在尝试写一个函数,这个函数是1。将一个项目添加到可观察数组中,然后单击2。替换阵列中已存在的项 self.addNotification = function (name, availability, note) { //see if we already have a line for this product var matchingItem = self.notifications.indexOf(name); if (matchingItem !== und
self.addNotification = function (name, availability, note) {
//see if we already have a line for this product
var matchingItem = self.notifications.indexOf(name);
if (matchingItem !== undefined) {
self.notifications.replace(self.notifications()[index(matchingItem)],
new Notification(self, name, availability, note));
}
else {
self.notifications.push(new Notification(self, name, availability, note));
}
};
我做错了什么
对于Anders来说,
Array.prototype.indexOf
永远不会返回未定义的。它要么是-1
(未找到),要么是数组索引中以0
开头的任何数字。以下是我的答案:
在Chrome中点击F12或在FireFox中使用FireBug查看控制台日志输出
var notifications = {
notifs: [],
updateNotifications: function(notification) {
'use strict';
var matchIndex;
for (matchIndex = 0; matchIndex < this.notifs.length; matchIndex += 1) {
if (this.notifs[matchIndex].name === notification.name) {
break;
}
}
if (matchIndex < this.notifs.length) {
this.notifs.splice(matchIndex, 1, notification);
} else {
this.notifs.push(notification);
}
}
};
notifications.updateNotifications({
name: 'John',
available: false,
note: "Huzzah!"
});
notifications.updateNotifications({
name: 'Jane',
available: true,
note: "Shazam!"
});
notifications.updateNotifications({
name: 'Jack',
available: true,
note: "Bonzai!"
});
notifications.updateNotifications({
name: 'Jane',
available: false,
note: "Redone!"
});
console.log(notifications);
var通知={
通知:[],
更新通知:功能(通知){
"严格使用",;
var匹配指数;
对于(matchIndex=0;matchIndex
好的,谢谢,我已将未定义更改为-1。。。但它只是不断地向数组中添加项。