用 if else +简单正则 就不香吗？一定要写一个难以维护的晦涩超长正则？

console.log("超难维护的一坨正则，一坨一坨的：")
exp=/@(?:(\d)|(\?)|(?:\w*?)(\d?[A-Z]+)(?:\w*))(?=@)/g;

arr=["BEGIN","GOogle","Google","3","3Protocol","?","abcd","345","?DD","6FIND0End"]

while(m=exp.exec("@"+arr.join("@")+"@"))console.log(m[1]||m[2]||m[3]||m[4]||m[5]||"")


console.log("简单易维护，逻辑条理清晰：")
for(var i=0;i<arr.length;i++){
str=arr[i]
val="";
if(str=="?"){
val=str
}else if(str.length==1 && /\d/.test(str)){
val=str
}else if(/^\w*?(\d?[A-Z]+)\w*$/.test(str)){
val=RegExp.$1
}
if(val){
console.log(val)
}
}