在javascript中将数组中的项目移动到顶部

Question

我需要从一个数组中删除一项，然后将其放入另一个数组的顶部。

我目前有一系列文章，其中一些文章的类型是“英雄”是真实的，其他的只是常规的。我需要找到数组中的第一篇英雄文章并将其删除。然后把这篇文章放到另一个数组的最上面。任何帮助将非常感激。谢谢

我目前有这个：

articles = [
    {title: "article 1", hero: false},
    {title: "article 2", hero: false},
    {title: "article 3", hero: true},
    {title: "article 4", hero: false},
    {title: "article 5", hero: true},
    {title: "article 6", hero: false},
    {title: "article 7", hero: true}
]

但想要这个结果：

articles = [
    {title: "article 1", hero: false},
    {title: "article 2", hero: false},
    {title: "article 4", hero: false},
    {title: "article 5", hero: true},
    {title: "article 6", hero: false},
    {title: "article 7", hero: true}
]

hero = [
    {title: "article 3", hero: true}
]

Answer 1

您可以使用

.findIndex()

来获取英雄等于

true

的第一篇文章。然后，您可以使用此索引将对象添加到您的

hero

数组中，然后再次使用它通过使用 articles

 从您的 

.splice() 数组中删除。

参见下面的示例：

const articles = [
    {title: "article 1", hero: false},
    {title: "article 2", hero: false},
    {title: "article 3", hero: true},
    {title: "article 4", hero: false},
    {title: "article 5", hero: true},
    {title: "article 6", hero: false},
    {title: "article 7", hero: true}
];
const hero = [];
const foundArticle = articles.findIndex(({hero}) => hero);
hero.push(articles[foundArticle]);
articles.splice(foundArticle, 1);

console.log(articles);
console.log(hero);

对于 IE 支持，您可以手动查找索引，而不是使用

.findIndex()

:

function findObjInArr(arr, cb) {
  for(let i = 0; i < arr.length; i++) {
    let obj = arr[i];
    if(cb(obj)) {
      return i;
    }
  }
  return -1;
}

const articles = [
    {title: "article 1", hero: false},
    {title: "article 2", hero: false},
    {title: "article 3", hero: true},
    {title: "article 4", hero: false},
    {title: "article 5", hero: true},
    {title: "article 6", hero: false},
    {title: "article 7", hero: true}
];

const hero = [];
const foundArticle = findObjInArr(articles, function(obj) {
  return obj.hero;
});
hero.push(articles[foundArticle]);
articles.splice(foundArticle, 1);

console.log(articles);
console.log(hero);

Answer 2

试试这个：

const articles = [
    {title: "article 1", hero: false},
    {title: "article 2", hero: false},
    {title: "article 3", hero: true},
    {title: "article 4", hero: false},
    {title: "article 5", hero: true},
    {title: "article 6", hero: false},
    {title: "article 7", hero: true},
];

const heros = [];

for(let [i, article] of articles.entries())
{
  if(article.hero)
    {
    heros.unshift(article);
    articles.splice(i, 1);
    break;
    }
}

console.log(heros);
console.log(articles);

Answer 3

var articles = [
    {title: "article 1", hero: false},
    {title: "article 2", hero: false},
    {title: "article 3", hero: true},
    {title: "article 4", hero: false},
    {title: "article 5", hero: true},
    {title: "article 6", hero: false},
    {title: "article 7", hero: true}
];
    
// Get the index of the first hero article, findIndex is not supported by IE 
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/findIndex#Browser_compatibility
var heroIndex = articles.findIndex(function (article) {
    return article.hero;
});

var hero = [];

if (heroIndex > -1) {
    // remove the first hero article from articles and add it to a new array
    hero = articles.splice(heroIndex, 1);
}

console.log("Hero article", hero);
console.log("Other articles", articles);

Answer 4

你可以尝试，

let articles = [
    {title: "article 1", hero: false},
    {title: "article 2", hero: false},
    {title: "article 3", hero: true},
    {title: "article 4", hero: false},
    {title: "article 5", hero: true},
    {title: "article 6", hero: false},
    {title: "article 7", hero: true}
];

let hero = [];
let heroArticle = {};

for(let article of articles){
  if(article.hero){
    heroArticle = article;
    hero.push(article);
    break;
    }
}

articles = articles.filter(a => a.title !== heroArticle.title);

console.log(articles);

Answer 5

articles = [
    {title: "article 1", hero: false},
    {title: "article 2", hero: false},
    {title: "article 4", hero: false},
    {title: "article 5", hero: true},
    {title: "article 6", hero: false},
    {title: "article 7", hero: true}
]
result = []

for(var article of articles) {
    if (article.hero) {
    articles.splice(articles.indexOf(article))
    result.push(article)
    }

}
console.log(articles)
console.log(result)

Answer 6

var hero = []
var founds = articles.find((e)=>{
  return e.hero ? e: false
})
hero.unshift(founds)

Answer 7

首先，选择文章数组的第三个元素 -

文章[2]；

定义一个空数组名称 Hero -

让 Hero = [] 或 Hero = new Array();

然后按-

hero.push(文章[2]);