JavaScript中元组的解构

Question

我想拆解一个元组：

tuple = [[1,"word",3,4,5],[1,"hello",3,4,5],[1,"word",3,4,5]]

就像这样：

let destruct = [item1, item2, item3, item4, item5] = [tuple]

但是所有的东西都是从元组分配给item1的。是否有可能实际将每个数组从元组映射到第二个数组中的5个项？

预期产出：

item2[0] = "word",
item2[1] = "hello

编辑:有人用tuples.map回答，得到了想要的结果，但答案被删除了吗？此外，一个纯粹的毁灭解决方案可能吗？

Answer 1

使用嵌套的map()，获取第一个索引，用它创建每个“列”：

const [ ] = tuple[0].map((_, i) => tuple.map((_, j) => tuple[j][i]))

​

const tuple = [[1,"word",3,4,5],[1,"hello",3,4,5],[1,"word",3,4,5]];

const [ item1, item2, item3, item4, item5 ] = tuple[0].map((_, i) => tuple.map((_, j) => tuple[j][i]));

console.log(item2[0], item2[1]); // word hello
console.log(item4);              // [ 4, 4, 4 ]

​

Answer 2

你在元组周围有额外的括号，试试这个

​

const tuple = [[1,"word",3,4,5],[2,"word",3,4,5],[3,"word",3,4,5]]
const [item1, item2, item3, item4, item5] = tuple

console.log(item3)

​

Answer 3

您可以在javascript中分解任何数组或对象。

let tuple = [[1,"word",3,4,5],[1,"word",3,4,5],[1,"word",3,4,5]]

let [item1, item2, item3] = tuple

您甚至可以获得嵌套值，如下所示

let [item1, [one, word, three], item3] = tuple;
console.log(one)  // 1
console.log(word)  // 'word'
console.log(three)  // 3