javascript code to check special characters

Question

I have JavaScript code to check if special characters are in a string. The code works fine in Firefox, but not in Chrome. In Chrome, even if the string does not contain special characters, it says it contains special characters.

var iChars = "~`!#$%^&*+=-[]\';,/{}|":<>?";

for (var i = 0; i < chkfile.value.length; i++)
{
  if (iChars.indexOf(chkfile.value.charAt(i)) != -1)
  {
     alert ("File name has special characters ~`!#$%^&*+=-[]\';,/{}|":<>? 
These are not allowed
");
     return false;
  }
}

Suppose I want to upload a file desktop.zip from any Linux/Windows machine. The value of chkfile.value is desktop.zip in Firefox, but in Chrome the value of chkfile.value is c://fakepath/desktop.zip. How do I get rid of c://fakepath/ from chkfile.value?

Answer 1

You can test a string using this regular expression:

function isValid(str){
 return !/[~`!#$%^&*+=-[]\';,/{}|":<>?]/g.test(str);
}