R string replacement: telephone number processing

Problem:

Now, I have a column of phone numbers:

12554189525

15527237602

15376581027

I want ~ 8 digits are replaced by *. How can this problem be solved?

Answer:

X <-as. character (C (12554189525,15527237602, 15376581027) substr (x, 5, 8) <-'*****' x

This is simple and efficient.

X <-. character (C (12554189525,15527237602, 15376581027) (Y <-paste (substr (x,), '***', substring (x, 9 ), SEP = ''))

This uses two substr and one paste, and the computing complexity increases a lot, resulting in poor performance.

X <-. character (C (12554189525,15527237602, 15376581027) for (I in 1: length (x) {x [I] <-sub (substr (X [I], 5, 8 ), "*****", X [I])} X

This method uses a loop, and the sub and substr functions are used in the loop. The efficiency is poor. This is still a traditional programming idea, and the vector programming style of R is not considered at all. The first answer is the vector programming style.