我正在嘗試使用 .push() 來保存多個值，但我得到了“{}”

Question

此toggle(...vals)獲取多個單詞並將這些單詞應用於var cur=...

function toggle(...vals) {
var unset = {};
var cur = unset;

return function next(){
    // save previous value back at
    // the end of the list
    vals.push(cur);
    return cur;
    };
}
var hello = toggle("hello");
console.log(hello());

我期望得到這個結果。

PS C:\Users\leePC\babel\public\src> node practice2_ch2.js
hello

但我得到了這個。

PS C:\Users\leePC\babel\public\src> node practice2_ch2.js
{}

建議的答案說我應該使用cur = vals.shift();

function toggle(...vals) {
var unset = {};
var cur = unset;

return function next(){
    // save previous value back at
    // the end of the list
    vals.push(cur);
    cur = vals.shift();
    return cur;
    };
}

var hello = toggle("hello");
console.log(hello());

令人驚訝的是它有效！

PS C:\Users\leePC\babel\public\src> node practice2_ch2.js
hello

但我仍然不確定為什么這個改變讓我得到了想要的結果......

Answer 1

嘗試使用：

function toggle(...vals) {
var unset = {};
var cur = unset;

return function next(){
    // save previous value back at
    // the end of the list
    vals.push(cur);
    return vals;
    };
}
var hello = toggle("hello");
console.log(hello());

插入：

function toggle(...vals) {
var unset = {};
var cur = unset;

return function next(){
    // save previous value back at
    // the end of the list
    vals.push(cur);
    return cur;
    };
}
var hello = toggle("hello");
console.log(hello());