javascript：通過索引從數組中獲取子數組

Question

是否有一行代碼可以通過索引從數組中獲取子數組？

例如，假設我想要得到["a","c","e"]從["a","b","c","d","e"]由[0,2,4] 。 如何用一行代碼做到這一點？ 像["a","b","c","d","e"][0,2,4] ..

Answer 1

你可以使用map ;

 var array1 = ["a","b","c"]; var array2 = [0,2]; var array3 = array2.map(i => array1[i]); console.log(array3);

Answer 2

您可以使用Array#filter和Array#includes

 const array = ['a','b','c']; console.log(array.filter((x,i) => [0,2].includes(i)));

Answer 3

您可以使用過濾器

 const arr = ['a', 'b', 'c']; const indexes = [0, 2]; const result = arr.filter((elt, i) => indexes.indexOf(i) > -1); document.body.innerHTML = result;

Answer 4

您可以使用Array.prototype.reduce()

 const arr = ['a', 'b', 'c', 'd', 'e']; const indexes = [0, 2, 4]; const result = indexes.reduce((a, b)=> { a.push(arr[b]); return a; }, []); console.log(result);