The type of output produced by the object is created or mentioned inside the return statement. If you want a character type output, then you must supply a character type object inside the return statement. In this recipe, the meanSe function calculates the mean and standard deviation, and then, it converts it into a character object by the following code lines:

    out <- paste("Mean of the input vector is = ",
           paste(avg), " with a standard error = ",
           paste(se), sep = "")

The paste function here has been used to print the text and convert the numeric output into character type. The out object contains a line of text with the value of mean and standard deviation in it.