Question

我想出了如何添加甚至修改对象数组中的实例，但是如何更改插槽“每个新的Student（）都会添加一个插槽”，因此从插槽0开始，最多可以达到3。而且，我将如何删除数组的实例？

var Student = function (name, address, city, state, gpa) {
    this.name = name;
    this.address = address;
    this.city = city;
    this.state = state;
    this.gpa = gpa;
    console.log(name, address, city, state, gpa);
};


var Student1 = [
    new Student("Some Guy","Some address","some city","some state",[2.5,3.1,4.0]),
    new Student("Some Guy","Some address","some city","some state",[2.5,3.1,4.0])
];

  Student1.push(new Student("Some Guy","Some address","some city","some state",[2.5,3.1,4.0]));

Answer 1

要删除数组中的第一个条目，您可以使用shift()。要删除数组中的最后一个条目，您可以使用pop()。要删除数组中的任何其他元素，可以使用splice(index,count)，第一个参数是要删除的索引，第二个参数是1：

var Students = [
    new Student("Some Guy1","Some address","some city","some state",[2.5,3.1,4.0]),
    new Student("Some Guy2","Some address","some city","some state",[2.5,3.1,4.0]),
    new Student("Some Guy3","Some address","some city","some state",[2.5,3.1,4.0])
];

var s2a = Students.splice(1,1); // after this line Students contains just Some Guy1 and Some Guy 3
var s3 = Students.pop(); // after this line Students contains just Some Guy1
var s1 = Students.shift(); // after this line Students is an empty array

请注意，虽然pop和shift会返回删除的实际元素，但splice会返回已删除元素的数组，在您的情况下会返回一个仅包含第二个学生的数组。

您可以在MDN上找到有关阵列和上述方法的大量信息。

Answer 2

你的问题不是很清楚。但我明白的是......你想从数组中删除现有的对象。如果我的理解是正确的，请尝试array.splice（index，howmany）。

示例：

var Diseases = ["Malaria", "Plague", "AIDS", "Cancer"];
Diseases.splice(2,1);

输出：[＆＃34;疟疾＆＃34;，＆＃34;瘟疫＆＃34;，＆＃34;癌症＆＃34;];

删除数组中的元素后，以下元素会自动移动其位置。希望这就是你要找的。

更改数组位置以及如何删除对象实例

2 个答案: