let str = "January,February,March,April,May,June,July,August,September,October,November,December"

let arr = str.split(',');

这将导致：

["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"]

如果要将以下内容转换为：

["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"]

这：

"January,February,March,April,May,June,July,August,September,October,November,December";

use:

str = arr.join(',')

请注意：

var a = "";
var x = new Array();
x = a.split(",");
alert(x.length);

将提醒1

一个很好的解决方案：

let obj = ['A','B','C']

obj.map((c) => { return c. }).join(', ')

我编写了php脚本来将字符串转换为数组，您可以将其运行到浏览器中，因此很容易

<form method="POST">
    <div>
        <label>String</label> <br>
        <input name="string" type="text">
    </div>
    <div style="margin-top: 1rem;">
        <button>konvert</button>
    </div>
</form>

<?php

$string = @$_POST['string'];

if ($string) {
    $result = json_encode(explode(",",$string));
    echo " '$result' <br>";
}
?>

下面是一个函数，它将字符串转换为数组，即使列表中只有一项（没有分隔符）：

function listToAray(fullString, separator) {
  var fullArray = [];

  if (fullString !== undefined) {
    if (fullString.indexOf(separator) == -1) {
      fullArray.push(fullString);
    } else {
      fullArray = fullString.split(separator);
    }
  }

  return fullArray;
}

这样使用：

var myString = 'alpha,bravo,charlie,delta';
var myArray = listToArray(myString, ',');
myArray[2]; // charlie

var yourString = 'echo';
var yourArray = listToArray(yourString, ',');
yourArray[0]; // echo

我创建这个函数是因为如果字符串中没有分隔符（只有一个项目），split会抛出一个错误。

将逗号分隔的字符串传递到此函数，它将返回一个数组，如果找不到逗号分隔字符串，则返回null。

function splitTheString(CommaSepStr) {
    var ResultArray = null;

    // Check if the string is null or so.
    if (CommaSepStr!= null) {

        var SplitChars = ',';

        // Check if the string has comma of not will go to else
        if (CommaSepStr.indexOf(SplitChars) >= 0) {
            ResultArray = CommaSepStr.split(SplitChars);

        }
        else {

            // The string has only one value, and we can also check
            // the length of the string or time and cross-check too.
            ResultArray = [CommaSepStr];
        }
    }
    return ResultArray;
}