How to check if a string contains only one type of character in R?

If a string contains more than one character then all of them could be same or different. If we want to check if a string contains only one type of character, then stri_count_fixed function of stringi package will be used with nchar function.

Check out the below given examples to understand how it can be done.

Example 1

Following snippet creates a sample data frame −

Countries<-sample(c("India","USA","UK","SSS"),20,replace=TRUE) df1<-data.frame(Countries) df1

The following dataframe is created −

  Countries 1  USA 2  India 3  India 4  SSS 5  USA 6  USA 7  USA 8  USA 9  India 10 SSS 11 SSS 12 India 13 SSS 14 USA 15 India 16 USA 17 SSS 18 USA 19 SSS 20 USA

To load stringi package and check whether all characters in each element of Countries is of one type or not, add the following code to the above snippet −

library(stringi) df1$All_S<-stri_count_fixed(df1$Countries,"S")==nchar(df1$Countries) df1

Output

If you execute all the above given snippets as a single program, it generates the following output: −

  Countries All_S 1  USA      FALSE 2  India    FALSE 3  India    FALSE 4  SSS      TRUE 5  USA      FALSE 6  USA      FALSE 7  USA      FALSE 8  USA      FALSE 9  India    FALSE 10 SSS      TRUE 11 SSS      TRUE 12 India    FALSE 13 SSS      TRUE 14 USA      FALSE 15 India    FALSE 16 USA      FALSE 17 SSS      TRUE 18 USA      FALSE 19 SSS      TRUE 20 USA      FALSE

Example 2

Following snippet creates a sample data frame −

Group<-sample(c("Control","Mixed","Common","XX"),20,replace=TRUE) df2<-data.frame(Group) df2

The following dataframe is created −

   Group 1  Mixed 2  XX 3  XX 4  Control 5  Mixed 6  Common 7  Common 8  Mixed 9  Mixed 10 XX 11 Mixed 12 Common 13 Common 14 XX 15 Mixed 16 Control 17 Mixed 18 Common 19 Control 20 Control

To check whether all characters in each element of Group is of one type or not, add the following code to the above snippet −

df2$All_X<-stri_count_fixed(df2$Group,"X")==nchar(df2$Group) df2

Output

If you execute all the above given snippets as a single program, it generates the following output: −

   Group    All_X 1  Mixed    FALSE 2  XX       TRUE 3  XX       TRUE 4  Control  FALSE 5  Mixed    FALSE 6  Common   FALSE 7  Common   FALSE 8  Mixed    FALSE 9  Mixed    FALSE 10 XX       TRUE 11 Mixed    FALSE 12 Common   FALSE 13 Common   FALSE 14 XX       TRUE 15 Mixed    FALSE 16 Control  FALSE 17 Mixed    FALSE 18 Common   FALSE 19 Control  FALSE 20 Control  FALSE