javascript - 如何删除 for 循环中的最后一个逗号？

Question

function currentLine(katzDeliLine) {
    if (katzDeliLine.length > 0) {
        var textToPrint = "The line is currently: "

        for (var crrLine = 0; crrLine < katzDeliLine.length; crrLine++) {

            textToPrint = textToPrint + (crrLine + 1) + ". " + katzDeliLine[crrLine] + ","

        }


        return textToPrint;
    } else {
        return "The line is empty"
    }
}

var lineofpeople = ["katrina", "kevin", "vincent"]

输出是: 当前行是:1. katrina，2. kevin，3. vincent，

我正在尝试去掉“文森特”之后的最后一个逗号

我试过 if 语句，我也试过 .join() 方法。我不知道如何在代码中实现它们。

Answer 1

您可以将前导数字映射到值，并用逗号连接数组。

function currentLine(array) {
    return array.length
        ? `The line is currently: ${array.map((v, i) => `${i + 1}. ${v}`).join(', ')}.`
        : "The line is empty.";
}

var lineofpeople = ["katrina", "kevin", "vincent"];

console.log(currentLine(lineofpeople));
console.log(currentLine([]));