将数组中的项目移动到javascript中的顶部

Question

我需要从一个数组中删除一个项目，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英雄是真实的，而其他文章则是常规的。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顶部。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

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 2

您可以使用.findIndex()来获取英雄等于 的第一篇文章true。然后，您可以使用此索引将对象添加到hero数组中，然后再次使用它从articles数组中删除.splice()。

请参阅下面的示例：

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);