Question

是否可以遍历数组，但不包括第一个元素（忽略数组中的第一个对象）？

代码：

 let multipleDemo =[];

 let people = [
    { name: 'Adam',      email: 'adam@email.com',      age: 12, 
country: 'United States' },
    { name: 'Amalie',    email: 'amalie@email.com',    age: 12, 
country: 'Argentina' },
    { name: 'Estefanía', email: 'estefania@email.com', age: 21, 
country: 'Argentina' },
    { name: 'Adrian',    email: 'adrian@email.com',    age: 21, 
country: 'Ecuador' },
    { name: 'Wladimir',  email: 'wladimir@email.com',  age: 30, 
country: 'Ecuador' },
    { name: 'Samantha',  email: 'samantha@email.com',  age: 30, 
country: 'United States' },
    { name: 'Nicole',    email: 'nicole@email.com',    age: 43, 
country: 'Colombia' },
    { name: 'Natasha',   email: 'natasha@email.com',   age: 54, 
country: 'Ecuador' },
   { name: 'Michael',   email: 'michael@email.com',   age: 15, 
country: 'Colombia' },
   { name: 'Nicolás',   email: 'nicolas@email.com',    age: 43, 
country: 'Colombia' }
  ];

for(var i =0; i < people.length; i++) {
     multipleDemo.push(people[i]);
     people.splice(people[i], 1000);
     console.log(multipleDemo);
     console.log(people);
}

示例代码：https://plnkr.co/edit/UJfRUs6dAT1NC1EnOvqA?p=preview

我想离开{名称：'Adam'，电子邮件：'adam@email.com'，年龄：12，国家/地区：'United States'}。我想放入arrayDemoDemo

数组中的其余元素

我想要诸如FINISH EFFECT：

 let multipleDemo =[,
    { name: 'Amalie',    email: 'amalie@email.com',    age: 12, 
country: 'Argentina' },
    { name: 'Estefanía', email: 'estefania@email.com', age: 21, 
country: 'Argentina' },
    { name: 'Adrian',    email: 'adrian@email.com',    age: 21, 
country: 'Ecuador' },
    { name: 'Wladimir',  email: 'wladimir@email.com',  age: 30, 
country: 'Ecuador' },
    { name: 'Samantha',  email: 'samantha@email.com',  age: 30, 
country: 'United States' },
    { name: 'Nicole',    email: 'nicole@email.com',    age: 43, 
country: 'Colombia' },
    { name: 'Natasha',   email: 'natasha@email.com',   age: 54, 
country: 'Ecuador' },
   { name: 'Michael',   email: 'michael@email.com',   age: 15, 
country: 'Colombia' },
   { name: 'Nicolás',   email: 'nicolas@email.com',    age: 43, 
country: 'Colombia' }];

 let people = [
    { name: 'Adam',      email: 'adam@email.com',      age: 12, 
country: 'United States' }
  ];

Answer 1

您可以使用Array.prototype.slice()修改数组以获得所需的输出。

let people = [{
    name: 'Adam',
    email: 'adam@email.com',
    age: 12,
    country: 'United States'
  },
  {
    name: 'Amalie',
    email: 'amalie@email.com',
    age: 12,
    country: 'Argentina'
  },
  {
    name: 'Estefanía',
    email: 'estefania@email.com',
    age: 21,
    country: 'Argentina'
  },
  {
    name: 'Adrian',
    email: 'adrian@email.com',
    age: 21,
    country: 'Ecuador'
  },
  {
    name: 'Wladimir',
    email: 'wladimir@email.com',
    age: 30,
    country: 'Ecuador'
  },
  {
    name: 'Samantha',
    email: 'samantha@email.com',
    age: 30,
    country: 'United States'
  },
  {
    name: 'Nicole',
    email: 'nicole@email.com',
    age: 43,
    country: 'Colombia'
  },
  {
    name: 'Natasha',
    email: 'natasha@email.com',
    age: 54,
    country: 'Ecuador'
  },
  {
    name: 'Michael',
    email: 'michael@email.com',
    age: 15,
    country: 'Colombia'
  },
  {
    name: 'Nicolás',
    email: 'nicolas@email.com',
    age: 43,
    country: 'Colombia'
  }
];

let multipleDemo = people.slice(1); 
people = people.slice(0, 1);
console.log(multipleDemo);
console.log('--------------------');
console.log(people);

Answer 2

您可以使用Array Destructuring进行解包，并使用rest模式将数组的其余部分分配给变量，然后使用.forEach()对其进行迭代，如下所示：

const arr = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10];

const [first, ...rest] = arr;

rest.forEach(v => console.log(v));

.as-console-wrapper { max-height: 100% !important; top: 0; }

Answer 3

有很多方法可以实现这一目标。但是最简单明了的解决方案是使用filter()。它返回一个数组，其中包含满足条件的每个元素。

 let people = [
    { name: 'Adam',      email: 'adam@email.com',      age: 12, 
country: 'United States' },
    { name: 'Amalie',    email: 'amalie@email.com',    age: 12, 
country: 'Argentina' },
    { name: 'Estefanía', email: 'estefania@email.com', age: 21, 
country: 'Argentina' },
    { name: 'Adrian',    email: 'adrian@email.com',    age: 21, 
country: 'Ecuador' },
    { name: 'Wladimir',  email: 'wladimir@email.com',  age: 30, 
country: 'Ecuador' },
    { name: 'Samantha',  email: 'samantha@email.com',  age: 30, 
country: 'United States' },
    { name: 'Nicole',    email: 'nicole@email.com',    age: 43, 
country: 'Colombia' },
    { name: 'Natasha',   email: 'natasha@email.com',   age: 54, 
country: 'Ecuador' },
   { name: 'Michael',   email: 'michael@email.com',   age: 15, 
country: 'Colombia' },
   { name: 'Nicolás',   email: 'nicolas@email.com',    age: 43, 
country: 'Colombia' }
  ];

let multipleDemo = people.filter((v, k) => k !== 0);
people = people.filter((v, k) => k === 0);

console.log(multipleDemo)
console.log(people)

Answer 4

您可以使用.slice()从一开始就省略 n 个元素。

select * from student s join studgroups sg on (s.studygroups = sg.studgroups_number) join study st on (sg.studgroupys_id = st.study_studgroups_id) where sg.studgroups_year !=s.study_kurs and s.study_state_id IN (1,2,3,4,5,6,7,21,22,23,24);表示您将数组从索引Array.slice(1)开始到结尾。

您还可以定义要分割的元素。

1将对索引Array.slice(1, 3)和1的元素进行切片。在这种情况下将是Amalie和Estefanía。

Answer 5

由于您只是想将元素从people数组复制到multipleDemo数组（不包括第一个元素），因此可以使用slice（）数组方法。

multipleDemo = people.slice(1)

.slice(1)将从索引1复制people数组的内容，而不引用multipleDemo数组。
.slice() in MDN

是否可以遍历数组，但不包括第一个元素？

5 个答案: