javascript - 使用正则表达式计算对象中的数组项

Question

所以我有一个对象:

   var data = {
      "movies": {
        "first": {
          "title": "Bruce Almigthy",
          "actors": ["Jim Carrey", "Morgan Freeman", "Jennifer Aniston"],
          "year": "2003"
        },
        "second": {
          "title": "The Truman Show",
          "actors": ["Jim Carrey", "Ed Harris","Morgan Freeman", "Laura Linney"],
          "year": "1998"
        },
        "third": {
          "title": "Ace Ventura",
          "actors": ["Jim Carrey", "Courteney Cox","Ed Harris"],
          "year": "1994"
        }
      }
    };

console.log(data.movies);

我需要找到出演过 1 部电影以上的 Actor ，以及只出演过一部电影的 Actor 。我通常用这样的方法处理此类问题:

function countMax(data) { 

    var actors = {}; 

    Object.keys(data.movies).forEach(function (key) { 
        var movie = data.movies[key]; 

        movie.actors.forEach(function (actor) { 
            if (!actors.hasOwnProperty(actor)) actors[actor] = 0; 
            actors[actor]++;    
        }) 

    }) 

    Object.keys(actors).forEach(function (actor) { 

        var count = actors[actor]; 
        if (count > 1) console.log(actor + ' stars in ' + count + ' movies.'); 

    });

}; 

countMax(data);

我想知道是否有不同的方法可以做到这一点，也许使用正则表达式或类似的东西？我只是不确定如何“接近”该物体。

Answer 1

我认为正则表达式不会为您做太多事情，但是您可以利用现代 Javascript 的一些优点来缩短一些事情。例如，您可以使用以下方法制作 Actor 和计数的 map :

var actor_map = Object.values(data.movies).reduce((a, c) => {
    c.actors.forEach(i => a[i] = a[i] ? a[i]+1 : 1 )
    return a
}, {})

然后您可以过滤计数以获得您想要的任何内容:

var more_that_one = Object.entries(actor_map).filter(([k, v]) => v > 1)
var less_that_one = Object.entries(actor_map).filter(([k, v]) => v == 1)

var data = {
    "movies": {
      "first": {
        "title": "Bruce Almigthy",
        "actors": ["Jim Carrey", "Morgan Freeman", "Jennifer Aniston"],
        "year": "2003"
      },
      "second": {
        "title": "The Truman Show",
        "actors": ["Jim Carrey", "Ed Harris","Morgan Freeman", "Laura Linney"],
        "year": "1998"
      },
      "third": {
        "title": "Ace Ventura",
        "actors": ["Jim Carrey", "Courteney Cox","Ed Harris"],
        "year": "1994"
      }
    }
  };

var actor_map = Object.values(data.movies).reduce((a, c) => {
    c.actors.forEach(i => a[i] = a[i] ? a[i]+1 : 1 )
    return a
}, {})

var more_that_one = Object.entries(actor_map).filter(([k, v]) => v > 1)
var less_that_one = Object.entries(actor_map).filter(([k, v]) => v == 1)

console.log(more_that_one)
console.log(less_that_one)