https://www.codewars.com/kata/57e3f79c9cb119374600046b

function hello(name) {   if(name == "" || name == null || name == undefined){       return "Hello, World!"   }else{      return "Hello, "+name.substring(0,1).toUpperCase()+name.substring(1).toLowerCase()+"!";   }}

↓更好的方法

function hello(name) {  if(name){    return "Hello, "+name.substring(0,1).toUpperCase()+name.substring(1).toLowerCase()+"!";  }else{    return "Hello, World!";  }}

↓更好的方法 (?纳尼)

const hello = s =>  `Hello, ${s ? (s[0].toUpperCase() + s.slice(1).toLowerCase()) : 'World'}!`;

https://www.cnblogs.com/ksl666/p/5944718.html

https://blog.csdn.net/cuit/article/details/53200335