split() 将字符串拆分成数组 join() 将数组合并 参数为分隔符 两套代码 #JavaScriptvar str = "ruben";var array = str.split('');array.forEach(s => console.log(s));str = array.join('');console.log(str); 以及 //javaString str = "ruben";String[] array = str.split("");for (String s : array) { System.out.println(s);}str = String.join("", array);System.out.println(str);