JavaScript中“ .filter（）[0]”之后“ [0]”是做什么的？

Question

我看到了这样的功能：

  getDish(id: number): Dish {
    return DISHES.filter((dish) => (dish.id === id))[0];
  }

但是我不明白为什么它在过滤器功能之后使用[0]？

编辑：这是DISHES：

export const DISHES: Dish[] = [
    {
        id: 0,
        name: 'Uthappizza',
        image: '/assets/images/uthappizza.png',
        category: 'mains',
        label: 'Hot',
        price: '4.99',
        featured: true,
        description: 'A unique combination of Indian Uthappam (pancake) and Italian pizza, topped with Cerignola olives, ripe vine cherry tomatoes, Vidalia onion, Guntur chillies and Buffalo Paneer.',
        comments: [
            {
                rating: 5,
                comment: "Imagine all the eatables, living in conFusion!",
                author: "John Lemon",
                date: "2012-10-16T17:57:28.556094Z"
            },
            {
                rating: 4,
                comment: "Sends anyone to heaven, I wish I could get my mother-in-law to eat it!",
                author: "Paul McVites",
                date: "2014-09-05T17:57:28.556094Z"
            },
            {
                rating: 3,
                comment: "Eat it, just eat it!",
                author: "Michael Jaikishan",
                date: "2015-02-13T17:57:28.556094Z"
            },
            {
                rating: 4,
                comment: "Ultimate, Reaching for the stars!",
                author: "Ringo Starry",
                date: "2013-12-02T17:57:28.556094Z"
            },
            {
                rating: 2,
                comment: "It's your birthday, we're gonna party!",
                author: "25 Cent",
                date: "2011-12-02T17:57:28.556094Z"
            }
        ]
    },
    {
        id: 1,
        name: 'Zucchipakoda',
        image: '/assets/images/zucchipakoda.png',
        category: 'appetizer',
        label: '',
        price: '1.99',
        featured: false,
        description: 'Deep fried Zucchini coated with mildly spiced Chickpea flour batter accompanied with a sweet-tangy tamarind sauce',
        comments: [
            {
                rating: 5,
                comment: "Imagine all the eatables, living in conFusion!",
                author: "John Lemon",
                date: "2012-10-16T17:57:28.556094Z"
            },
            {
                rating: 4,
                comment: "Sends anyone to heaven, I wish I could get my mother-in-law to eat it!",
                author: "Paul McVites",
                date: "2014-09-05T17:57:28.556094Z"
            },
            {
                rating: 3,
                comment: "Eat it, just eat it!",
                author: "Michael Jaikishan",
                date: "2015-02-13T17:57:28.556094Z"
            },
            {
                rating: 4,
                comment: "Ultimate, Reaching for the stars!",
                author: "Ringo Starry",
                date: "2013-12-02T17:57:28.556094Z"
            },
            {
                rating: 2,
                comment: "It's your birthday, we're gonna party!",
                author: "25 Cent",
                date: "2011-12-02T17:57:28.556094Z"
            }
        ]
    },
    {
        id: 2,
        name: 'Vadonut',
        image: '/assets/images/vadonut.png',
        category: 'appetizer',
        label: 'New',
        price: '1.99',
        featured: false,
        description: 'A quintessential ConFusion experience, is it a vada or is it a donut?',
        comments: [
            {
                rating: 5,
                comment: "Imagine all the eatables, living in conFusion!",
                author: "John Lemon",
                date: "2012-10-16T17:57:28.556094Z"
            },
            {
                rating: 4,
                comment: "Sends anyone to heaven, I wish I could get my mother-in-law to eat it!",
                author: "Paul McVites",
                date: "2014-09-05T17:57:28.556094Z"
            },
            {
                rating: 3,
                comment: "Eat it, just eat it!",
                author: "Michael Jaikishan",
                date: "2015-02-13T17:57:28.556094Z"
            },
            {
                rating: 4,
                comment: "Ultimate, Reaching for the stars!",
                author: "Ringo Starry",
                date: "2013-12-02T17:57:28.556094Z"
            },
            {
                rating: 2,
                comment: "It's your birthday, we're gonna party!",
                author: "25 Cent",
                date: "2011-12-02T17:57:28.556094Z"
            }
        ]
    },
    {
        id: 3,
        name: 'ElaiCheese Cake',
        image: '/assets/images/elaicheesecake.png',
        category: 'dessert',
        label: '',
        price: '2.99',
        featured: false,
        description: 'A delectable, semi-sweet New York Style Cheese Cake, with Graham cracker crust and spiced with Indian cardamoms',
        comments: [
            {
                rating: 5,
                comment: "Imagine all the eatables, living in conFusion!",
                author: "John Lemon",
                date: "2012-10-16T17:57:28.556094Z"
            },
            {
                rating: 4,
                comment: "Sends anyone to heaven, I wish I could get my mother-in-law to eat it!",
                author: "Paul McVites",
                date: "2014-09-05T17:57:28.556094Z"
            },
            {
                rating: 3,
                comment: "Eat it, just eat it!",
                author: "Michael Jaikishan",
                date: "2015-02-13T17:57:28.556094Z"
            },
            {
                rating: 4,
                comment: "Ultimate, Reaching for the stars!",
                author: "Ringo Starry",
                date: "2013-12-02T17:57:28.556094Z"
            },
            {
                rating: 2,
                comment: "It's your birthday, we're gonna party!",
                author: "25 Cent",
                date: "2011-12-02T17:57:28.556094Z"
            }
        ]
    }
];

Answer 1

filter返回过滤后的数组。 [0]访问该数组的第一个元素。