Introduction
R provides powerful capabilities for working with character strings. The stringr package makes string manipulation intuitive.
Creating Strings
# Using quotes
str1 <- "Hello"
str2 <- 'World'
# Multiple strings
fruits <- c("apple", "banana", "orange")
# Escape characters
quote <- "She said \"Hello\""
String Functions (base R)
str <- "Hello World"
nchar(str) # Length: 11
toupper(str) # "HELLO WORLD"
tolower(str) # "hello world"
substr(str, 1, 5) # "Hello"
paste("Hello", "World") # "Hello World"
paste0("Hello", "World") # "HelloWorld"
strsplit(str, " ") # Split into list
Stringr Package
library(stringr)
str <- "Hello World"
str_length(str) # Length
str_to_upper(str) # Uppercase
str_to_lower(str) # Lowercase
str_sub(str, 1, 5) # Substring
str_detect(str, "Hello") # Detect pattern
str_replace(str, "World", "R") # Replace
str_extract(str, "[A-Z]+") # Extract pattern
String Formatting
name <- "Alice"
age <- 30
# sprintf
sprintf("Name: %s, Age: %d", name, age)
# paste with collapse
items <- c("a", "b", "c")
paste(items, collapse = ", ")
Pattern Matching
library(stringr)
text <- "The quick brown fox"
str_detect(text, "quick") # TRUE
str_starts(text, "The") # TRUE
str_ends(text, "fox") # TRUE
str_count(text, "o") # Count occurrences
Summary
String manipulation is essential for text processing. Use stringr for consistent and readable code.