Replacing with regular expressions

Now, you've mastered matching with backreferences, you'll build up to replacing with backreferences, but first let's review str_replace() now that you've got regular expressions under your belt.

Remember str_replace() takes three arguments, string a vector of strings to do the replacements in, pattern that identifies the parts of strings to replace and replacement the thing to use as a replacement.

replacement can be a vector, the same length as string, each element specifies the replacement to be used in each string. Let's practice by anonymizing some of the contact objects you've seen so far.

この演習はコースの一部です

String Manipulation with stringr in R

コースを見る

演習の手順

Text containing phone numbers has been pre-defined in a variable named contact.

Replace a digit in contact with "X" using str_replace().
Replace all digits in contact with "X" using str_replace_all(). (str_replace() will only replace the first match to the pattern. str_replace_all() will replace all matches to the pattern.)
Replace all digits in contact using str_replace_all(), but now specify the vector c("X", ".", "*", "_") as replacement. Notice how now each string uses a different replacement character.

実践的なインタラクティブ演習

このサンプルコードを完成させて、この演習に挑戦してみましょう。

# View text containing phone numbers
contact

# Replace digits with "X"
str_replace(contact, DGT, ___)

# Replace all digits with "X"
str_replace_all(contact, DGT, ___)

# Replace all digits with different symbol
str_replace_all(contact, DGT, ___)

コードを編集して実行