Extension–Getting-to-know-with-what-is-substring.R

### Extension: Getting to know with what is substring

## create a data frame
df <- data.frame (team = c ("Ahmad", "Bachelot", "Charles", "Douglass", "Friedman"))

# view the data frame
df

##       team
## 1    Ahmad
## 2 Bachelot
## 3  Charles
## 4 Douglass
## 5 Friedman

# string is something like a line, and the string in columns are the characters
# with the same position in each box (e.g.: they're all the first letter in that box)

################### Example 1: Extract characters between certain positons

# create a new column that contains characters between positions 2 and 5
df$between2_5 <- substring( df$team, first = 2, last = 5)

# view the resulting data frame
df

##       team between2_5
## 1    Ahmad       hmad
## 2 Bachelot       ache
## 3  Charles       harl
## 4 Douglass       ougl
## 5 Friedman       ried

################### Example 2: Extract first N characters

df$first3 <- substring(df$team, first = 1, last = 3)

# view the resulting data frame
df

##       team between2_5 first3
## 1    Ahmad       hmad    Ahm
## 2 Bachelot       ache    Bac
## 3  Charles       harl    Cha
## 4 Douglass       ougl    Dou
## 5 Friedman       ried    Fri

################### Example 3: Extract last 3 characters

df$last3 <- substring(df$team, nchar(df$team) -3+1 , nchar(df$team))

# view the resulting data frame
df

##       team between2_5 first3 last3
## 1    Ahmad       hmad    Ahm   mad
## 2 Bachelot       ache    Bac   lot
## 3  Charles       harl    Cha   les
## 4 Douglass       ougl    Dou   ass
## 5 Friedman       ried    Fri   man

################### Example 4: Replace the substring

substring(df$team, first = 1, last = 3) <- "***"

# view the resulting data frame
df

##       team between2_5 first3 last3
## 1    ***ad       hmad    Ahm   mad
## 2 ***helot       ache    Bac   lot
## 3  ***rles       harl    Cha   les
## 4 ***glass       ougl    Dou   ass
## 5 ***edman       ried    Fri   man