How to know if a URL is decoded/encoded?

Question

I am using Javascript method decodeURIComponent to decode an encoded URL. Now I am having an issue, that sometimes the URL is get encoded twice during redirection b

Answer 1

you can keep decode until the string did not change:

str = "xxxxxxx"
dec_str = decode(str)
while(dec_str != str)
     str = dec_str;
     dec_str = decode(str);