ggorlen/r-gotchas.md

## r-gotchas.md

      
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              r-gotchas.md
            
          
    R gotchas

Weird vectorized string appends

Wrong:
result <- c()
result <- c(result, "foo")
result <- c(result, paste0(rep("X", 3), "z")) # => [1] "foo" "Xz"  "Xz"  "Xz" 
print(result) # => [1] "foo\nXz\nXz\nXz"
print(paste(result, collapse="\n"))
Fix:
result <- c()
result <- c(result, "foo")
result <- c(result, paste0(paste0(rep("X", 3), collapse=""), "z"))
# or: result <- c(result, paste0(strrep("X", 3), "z"))
print(result) # => [1] "asdf" "XXXz"
print(paste(result, collapse="\n")) # => [1] "asdf\nXXXz"