//如果是直接赋值语句，如 a=b, 则这两者会关联到一起！a会随b的变化而变化！
let a = ["one", "two", "three"]
let b = a
b.push(6)
console.log(123, a, b)
//123 [ 'one', 'two', 'three', 6 ] [ 'one', 'two', 'three', 6 ]

// 如果不想这者关联，要使用slice, 它会创建一个新的数组
let a = ["one", "two", "three"]
let b = a.slice()
b.push(6)
console.log(123, a, b)
// 123 [ 'one', 'two', 'three' ] [ 'one', 'two', 'three', 6 ]