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 = ....
这是我对这个问题的回应。我的下划线版本是1.7,因此我不能使用. findindex。
所以我手动获取了item的索引并替换了它。这里是相同的代码。
var students = [
{id:1,fName:"Ajay", lName:"Singh", age:20, sex:"M" },
{id:2,fName:"Raj", lName:"Sharma", age:21, sex:"M" },
{id:3,fName:"Amar", lName:"Verma", age:22, sex:"M" },
{id:4,fName:"Shiv", lName:"Singh", age:22, sex:"M" }
]
下面的方法将用对象中更多的属性替换id:4的学生
function updateStudent(id) {
var indexOfRequiredStudent = -1;
_.each(students,function(student,index) {
if(student.id === id) {
indexOfRequiredStudent = index; return;
}});
students[indexOfRequiredStudent] = _.extend(students[indexOfRequiredStudent],{class:"First Year",branch:"CSE"});
}
使用下划线1.8,它将被简化,因为我们有方法_.findIndexOf。
首先查找索引:
function getIndex(array, key, value) {
var found = false;
var i = 0;
while (i<array.length && !found) {
if (array[i][key]==value) {
found = true;
return i;
}
i++;
}
}
然后:
console.log(getIndex($scope.rides, "_id", id));
然后对这个索引做你想做的事情,比如:
美元(returnedindex)范围。someKey = "someValue";
注意:请不要使用for,因为for将检查所有的数组文档,使用while带有一个停止器,因此一旦找到它就会停止,从而更快地编写代码。
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);