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 = ....


当前回答

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 ) );

其他回答

假设您希望在修改期间运行更复杂的代码,您可能会使用if-else语句而不是三元操作符方法

// original 'projects' array;
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"
    }
];
// modify original 'projects' array, and save modified array into 'projects' variable
projects = projects.map(project => {
// When there's an object where key 'value' has value 'jquery-ui'
    if (project.value == 'jquery-ui') {

// do stuff and set a new value for where object's key is 'value'
        project.value = 'updated value';

// do more stuff and also set a new value for where the object's key is 'label', etc.
        project.label = 'updated label';

// now return modified object
        return project;
    } else {
// just return object as is
        return project;
    }
});

// log modified 'projects' array
console.log(projects);
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
);

要更新多个匹配项,请使用:

_.chain(projects).map(item => {
      item.desc = item.value === "jquery-ui" ? "new desc" : item.desc;
      return item;
    })

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 ) );

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));