你可以使用$.each()遍历数组并定位你感兴趣的对象:

$.each(projects, function() {
    if (this.value == "jquery-ui") {
        this.desc = "Your new description";
    }
});

用每个循环使用的条件更改值

projects.forEach((p,index)=>{
    if(index === 1){
       p.value = "Updated jquery-ui"
    }
})

尝试使用forEach(item,index) helper

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"
    }
];

let search_to_change = 'jquery'

projects.forEach((item,index)=>{
   if(item.value == search_to_change )
      projects[index].desc = 'your description ' 
})

const state = [
{
    userId: 1,
    id: 100,
    title: "delectus aut autem",
    completed: false
},
{
    userId: 1,
    id: 101,
    title: "quis ut nam facilis et officia qui",
    completed: false
},
{
    userId: 1,
    id: 102,
    title: "fugiat veniam minus",
    completed: false
},
{
    userId: 1,
    id: 103,
    title: "et porro tempora",
    completed: true
}]

const newState = state.map(obj =>
    obj.id === "101" ? { ...obj, completed: true } : obj
);

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 ) );

根据以下数据，我们想用西瓜替换summerFruits列表中的浆果。

const summerFruits = [
{id:1,name:'apple'}, 
{id:2, name:'orange'}, 
{id:3, name: 'berries'}];

const fruit = {id:3, name: 'watermelon'};

有两种方法。

第一种方法:

//create a copy of summer fruits.
const summerFruitsCopy = [...summerFruits];

//find index of item to be replaced
const targetIndex = summerFruits.findIndex(f=>f.id===3); 

//replace the object with a new one.
summerFruitsCopy[targetIndex] = fruit;

第二种方法:使用map和spread:

const summerFruitsCopy = summerFruits.map(fruitItem => 
fruitItem .id === fruit.id ? 
    {...summerFruits, ...fruit} : fruitItem );

summerFruitsCopy列表现在将返回一个更新对象的数组。