从 JavaScript 中的数组中选择随机元素返回整个数组

Question

我正在编写一个程序来使用 JavaScript 猜测输入，为此我必须从数组中选择一个随机元素。 但是，在尝试使用 Chrome DevTools 对其进行调试后，我发现它返回的是整个数组，而不仅仅是元素。 编辑：我还确保它与用于 select 随机元素的方法无关。 这是一些代码：

        var alphabet = ["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z","A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z","0","1","2","3","4","5","6","7","8","9","~","`","!","@","#","$","%","^","&","*","(",")","-","_","=","+","[","]","{","}","\\","|",";",":","'","\"",",","<",".",">","/","?"," "]
        var charset = [];
        if(document.getElementById("lowercase").checked){
            charset.push(alphabet.slice(0, 26));
        }
        if(document.getElementById("uppercase").checked){
            charset.push(alphabet.slice(26, 52));
        }
        if(document.getElementById("numbers").checked){
            charset.push(alphabet.slice(52, 62));
        }
        if(document.getElementById("special").checked){
            charset.push(alphabet.slice(62, alphabet.length));
        }
        var word = document.getElementById("input").value;
        var foundword = "";
        while(true) {
            for(i = 0; i < word.length; i++) {
                foundword += charset[Math.floor(Math.random() * charset.length)];
            }
            if(word == foundword) {
                alert("done");
                break;
            }
            foundword = "";
        }

有人可以帮忙吗？ 提前致谢！

Answer 1

alphabet.slice返回一个数组。

当您charset.push(alphabet.slice(.......))时，您正在推送一个数组，因此最后的charset是一个 arrays 数组。

您可以使用扩展运算符 - ... - 将推送的数组转换为一系列值：

charset.push(...alphabet.slice(26, 52));

只是为了帮助您习惯语法，这里有几个例子：

let arr = alphabet.slice(26, 52);
charset.push(...arr);

charset.push(...['a', 'b', 'c']);