vue知识点总结 --- 扩展运算符 … (三个点)

扩展运算符 … (三个点)

• 操作数组

...[1,2,3] => 1,2,3

• 与解构赋值结合

var [a, ...arr] = [1,2,3,4,5]
a => 1
arr => [2,3,4,5]

var [a, ...arr] = []
a => undefined
arr => []

var [a, ...arr] = ['A']
a => 'A'
arr => []

• 复制数组
  1）循环
  2）Array.from(arr)
  3）var arr2 = […arr]

• 字符串转数组

[...'hello'] => ['h','e','l','l','o']