下面的 Reg 表达式有什么问题？

Question

I'm trying to replicate a Reg Ex.. But my code is giving always true irrespective of the value i pass..

It would be much helpful.. if u can explain what exactly this reg Ex is doing...

 var re = new RegExp("([a-zA-Z0-9-`.'_]?)+"); if(re.test('valueFromHtml'){ console.log("valid"); }else{ console.log("invalid"); }

Answer 1

var re = new RegExp("([a-zA-Z0-9-`.'_]?)+");

Your regular expression means, "one or more occurrences of a member of this particular set of characters, or no characters". Your pattern therefore matches the zero-character empty string, which is part of any possible test string.