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);

你可以使用map函数——

const answers = this.state.answers.map(answer => {
  if(answer.id === id) return { id: id, value: e.target.value }
  return answer
})

this.setState({ answers: answers })

它可以很容易地用下划线/lodash库完成:

  _.chain(projects)
   .find({value:"jquery-ui"})
   .merge({desc: "new desc"}).value();

文档: https://lodash.com/docs#find https://lodash.com/docs#merge

最简单的方法就是这样做

    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"
}];

projects.find(data => data.value === "jquery").label ="xxxx"

console.log("------------>",projects)

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";
    }
});

你可以在你的例子中使用。find so

   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 project = projects.find((p) => {
    return p.value === 'jquery-ui';
});

project.desc = 'your value'