Presumably you're using loadStrings()?  Read the documentation:

 Reads the contents of a file or url and creates a String array of its individual lines.

The example demonstrates how to access the contents of the String array ;)

you are looping through the array printing out each line after another

for (int i=0; i < lines.length; i++) {
  println(lines[i]);
}

is it possible in processing to read a text file which is not present in its data folder???????

yes.
when it's on your hard drive, use a absolute path (in a special form, check the forum).
You can even load from the web.

thanks, I couldn't remember what the form was  

priyankapardesi, in addition to the points I raised in the other topic, I can indeed add: don't revive one-year old threads, not directly related to your topic, with a question duplicate of two other topics.
And again in another topic! I deleted this answer of your...