正则表达式删除连续字符

Question

Need a regular expression to replace the following sequence

Before : abbbccdd   After : abcd

And also if numeric data is present instead of alphabets i would like to remove the duplicates and display

Answer 1

For the first part, in most languages you can do something like replacing (.)\\1+ with $1 .

The exact syntax depends on the language and the regular expression engine you are using, so check the manual for your language for more details.

Answer 2

This works in PHP:

preg_replace('/(.)\1+/','$1',$str);

I'm not sure what you mean with your second question, though.