This function adds two objects. If both objects are numeric vectors,
it performs element-wise addition. If one or both objects are strings,
it concatenates them. For other objects, it attempts to use the +
method defined for the class of the objects.
# Add two numeric vectorsadd(c(1, 2, 3), c(4, 5, 6))
# Concatenate two stringsadd("hello", "world")
# Add a number and a string (concatenation)add(1, " world")