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 = ....
这是另一个涉及到发现的答案。
这取决于以下事实:
遍历数组中的每个对象,直到找到匹配的对象
每个对象都提供给你并且是可修改的
下面是关键的Javascript代码片段:
projects.find( function (p) {
if (p.value !== 'jquery-ui') return false;
p.desc = 'your value';
return true;
} );
下面是相同Javascript的另一个版本:
projects.find( function (p) {
if (p.value === 'jquery-ui') {
p.desc = 'your value';
return true;
}
return false;
} );
这里有一个更短的(有点邪恶的版本):
projects.find( p => p.value === 'jquery-ui' && ( p.desc = 'your value', true ) );
以下是完整的工作版本:
let 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"
}
];
projects.find( p => p.value === 'jquery-ui' && ( p.desc = 'your value', true ) );
console.log( JSON.stringify( projects, undefined, 2 ) );
这很简单
使用findIndex方法查找对象的索引。
将索引存储在变量中。
做一个简单的更新,像这样:
//Initailize array of objects.
let myArray = [
{id: 0, name: "Jhon"},
{id: 1, name: "Sara"},
{id: 2, name: "Domnic"},
{id: 3, name: "Bravo"}
],
//Find index of specific object using findIndex method.
objIndex = myArray.findIndex((obj => obj.id == 1));
//Log object to Console.
console.log("Before update: ", myArray[objIndex])
//Update object's name property.
myArray[objIndex].name = "Laila"
//Log object to console again.
console.log("After update: ", myArray[objIndex])
javascript解构的力量
const projects = [
{
value: 'jquery',
label: 'jQuery',
desc: 'the write less, do more, JavaScript library',
icon: 'jquery_32x32.png',
anotherObj: {
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',
},
];
function createNewDate(date) {
const newDate = [];
date.map((obj, index) => {
if (index === 0) {
newDate.push({
...obj,
value: 'Jquery??',
label: 'Jquery is not that good',
anotherObj: {
...obj.anotherObj,
value: 'Javascript',
label: 'Javascript',
desc: 'Write more!!! do more!! with JavaScript',
icon: 'javascript_4kx4k.4kimage',
},
});
} else {
newDate.push({
...obj,
});
}
});
return newDate;
}
console.log(createNewDate(projects));
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