给定一个少于160项的数组,我想提取三个字段并复制它们;
const item1 = {name:'Item-1'};
const item2 = {name:'Item-1'};
const item1 = {name:'Item-1'};
...........
const item_N_minus_one = {name:'Item-N_minus_one'};
const item_N = {name:'Item-N'};
const itemsList = [{item1}, {item2} ..... upto {itemN}]
// Where n <= 160
下面是我的方法,它正在工作
const index_X = 23, index_Y = 45, index_Z= 56; // Can not exceed beyond 160 in my case
const item_XCopy = {...itemsList[index_X]};
const item_YCopy = {...itemsList[index_Y]};
const item_ZCopy = {...itemsList[index_Z]};
我想要的:寻找一个单行快捷方式解决方案,我可以在一个javascript语句中传递索引,并在另一个数组中返回字段(我知道我可以生成一个函数,但只是想知道是否有javascript快捷方式解决方案(
您可以获得项目,而不是副本,如下所示:
const itemsList = [{name:'Item-1'}, {name:'Item-2'}, {name:'Item-3'}];
const index_X = 0, index_Y = 1, index_Z= 2;
const { [index_X]: index_X_Item, [index_Y]: index_Y_Item, [index_Z]: index_Z_Item }
= itemsList;
console.log(index_X_Item, index_Y_Item, index_Z_Item);
要获得副本,您可以使用Array#map
:
const itemsList = [{name:'Item-1'}, {name:'Item-2'}, {name:'Item-3'}];
const index_X = 0, index_Y = 1, index_Z= 2;
const [index_X_Copy, index_Y_Copy, index_Z_Copy] =
[index_X, index_Y, index_Z].map(index => ({ ...itemsList[index] }));
console.log(index_X_Copy, index_Y_Copy, index_Z_Copy);
您可以直接寻址并分配给新的变量名。
const
index_X = 23,
index_Y = 45,
index_Z = 56,
{
[index_X]: { ...item_XCopy },
[index_Y]: { ...item_YCopy },
[index_Z]: { ...item_ZCopy }
} = itemsList;