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 = ....
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。
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));
这里有一个简洁明了的答案。我不是百分百确定这能行，但看起来还行。请让我知道，如果一个库是必需的，但我不认为是。另外，如果这在x浏览器中不起作用，请告诉我。我在Chrome IE11和Edge上尝试了这个功能，它们似乎都能正常工作。
var Students = [
{ ID: 1, FName: "Ajay", LName: "Test1", Age: 20},
{ ID: 2, FName: "Jack", LName: "Test2", Age: 21},
{ ID: 3, FName: "John", LName: "Test3", age: 22},
{ ID: 4, FName: "Steve", LName: "Test4", Age: 22}
]
Students.forEach(function (Student) {
if (Student.LName == 'Test1') {
Student.LName = 'Smith'
}
if (Student.LName == 'Test2') {
Student.LName = 'Black'
}
});
Students.forEach(function (Student) {
document.write(Student.FName + " " + Student.LName + "<BR>");
});
输出应该如下所示
Ajay史密斯
杰克·布莱克
约翰Test3
史蒂夫Test4
