下面的代码来自jQuery UI自动完成:
var projects = [
{
value: "jquery",
label: "jQuery",
desc: "the write less, do more, JavaScript library",
icon: "jquery_32x32.png"
},
{
value: "jquery-ui",
label: "jQuery UI",
desc: "the official user interface library for jQuery",
icon: "jqueryui_32x32.png"
},
{
value: "sizzlejs",
label: "Sizzle JS",
desc: "a pure-JavaScript CSS selector engine",
icon: "sizzlejs_32x32.png"
}
];
例如,我想更改jquery-ui的desc值。我该怎么做呢?
此外,是否有更快的方法来获取数据?我的意思是给对象一个名字来获取它的数据,就像数组中的对象一样?比如jquery-ui。jquery-ui。desc = ....
首先查找索引:
function getIndex(array, key, value) {
var found = false;
var i = 0;
while (i<array.length && !found) {
if (array[i][key]==value) {
found = true;
return i;
}
i++;
}
}
然后:
console.log(getIndex($scope.rides, "_id", id));
然后对这个索引做你想做的事情,比如:
美元(returnedindex)范围。someKey = "someValue";
注意:请不要使用for,因为for将检查所有的数组文档,使用while带有一个停止器,因此一旦找到它就会停止,从而更快地编写代码。
let users = [
{id: 1, name: 'Benedict'},
{id: 2, name: 'Myles'},
{id: 3, name: 'Happy'},
]
users.map((user, index) => {
if(user.id === 1){
users[index] = {id: 1, name: 'Baba Benny'};
}
return user
})
console.log(users)
这段代码所做的是映射对象,然后匹配所需的
使用if语句,
if(user.id === 1)
一旦有匹配的地方使用它的索引交换
users[index] = {id: 1, name: 'Baba Benny'};
对象,然后返回修改后的数组
这是我对这个问题的回应。我的下划线版本是1.7,因此我不能使用. findindex。
所以我手动获取了item的索引并替换了它。这里是相同的代码。
var students = [
{id:1,fName:"Ajay", lName:"Singh", age:20, sex:"M" },
{id:2,fName:"Raj", lName:"Sharma", age:21, sex:"M" },
{id:3,fName:"Amar", lName:"Verma", age:22, sex:"M" },
{id:4,fName:"Shiv", lName:"Singh", age:22, sex:"M" }
]
下面的方法将用对象中更多的属性替换id:4的学生
function updateStudent(id) {
var indexOfRequiredStudent = -1;
_.each(students,function(student,index) {
if(student.id === id) {
indexOfRequiredStudent = index; return;
}});
students[indexOfRequiredStudent] = _.extend(students[indexOfRequiredStudent],{class:"First Year",branch:"CSE"});
}
使用下划线1.8,它将被简化,因为我们有方法_.findIndexOf。
ES6方式,不改变原始数据。
var projects = [
{
value: "jquery",
label: "jQuery",
desc: "the write less, do more, JavaScript library",
icon: "jquery_32x32.png"
},
{
value: "jquery-ui",
label: "jQuery UI",
desc: "the official user interface library for jQuery",
icon: "jqueryui_32x32.png"
}];
//find the index of object from array that you want to update
const objIndex = projects.findIndex(obj => obj.value === 'jquery-ui');
// Make sure to avoid incorrect replacement
// When specific item is not found
if (objIndex === -1) {
return;
}
// make new object of updated object.
const updatedObj = { ...projects[objIndex], desc: 'updated desc value'};
// make final new array of objects by combining updated object.
const updatedProjects = [
...projects.slice(0, objIndex),
updatedObj,
...projects.slice(objIndex + 1),
];
console.log("original data=", projects);
console.log("updated data=", updatedProjects);