library(XML)
library(jsonlite)

html_data <- readHTMLTable("books.HTML")
html_df <- as.data.frame(html_data)
html_df
##                                                                                                NULL.Title
## 1 The Complete Guide to Fasting: Heal Your Body Through Intermittent, Alternate-Day, and Extended Fasting
## 2                                             Delay, Don't Deny: Living an Intermittent Fasting Lifestyle
## 3               Fasting: Opening the door to a deeper, more intimate, more powerful relationship with God
##                NULL.Author.s. NULL.Date.Published
## 1 Dr. Jason Fung; Jimmy Moore          10/18/2016
## 2                Gin Stephens          12/31/2016
## 3           Jentezen Franklin          12/14/2007
##                                NULL.Publisher  NULL.ISBN
## 1                     Victory Belt Publishing 1628600012
## 2 CreateSpace Independent Publishing Platform 1541325842
## 3                              Charisma House 1599792583
xml_data <- xmlParse("books.xml")
xml_df <- xmlToDataFrame(xml_data)
xml_df
##                                                                                                     TITLE
## 1 The Complete Guide to Fasting: Heal Your Body Through Intermittent, Alternate-Day, and Extended Fasting
## 2                                             Delay, Don't Deny: Living an Intermittent Fasting Lifestyle
## 3               Fasting: Opening the door to a deeper, more intimate, more powerful relationship with God
##                        AUTHOR DATE_PUBLISHED
## 1 Dr. Jason Fung; Jimmy Moore     10/18/2016
## 2                Gin Stephens     12/31/2016
## 3           Jentezen Franklin     12/14/2007
##                                     PUBLISHER       ISBN
## 1                     Victory Belt Publishing 1628600012
## 2 CreateSpace Independent Publishing Platform 1541325842
## 3                              Charisma House 1599792583
json_data <- fromJSON("books.json")
json_df <- as.data.frame(json_data)
json_df
##                                                                                               books.Title
## 1 The Complete Guide to Fasting: Heal Your Body Through Intermittent, Alternate-Day, and Extended Fasting
## 2                                             Delay, Don't Deny: Living an Intermittent Fasting Lifestyle
## 3               Fasting: Opening the door to a deeper, more intimate, more powerful relationship with God
##               books.Author.s. books.Date.Published
## 1 Dr. Jason Fung; Jimmy Moore           10/18/2016
## 2                Gin Stephens           12/31/2016
## 3           Jentezen Franklin           12/14/2007
##                               books.Publisher books.ISBN
## 1                     Victory Belt Publishing 1628600012
## 2 CreateSpace Independent Publishing Platform 1541325842
## 3                              Charisma House 1599792583

Conclusions

The three data frames are nearly identical. The only difference is that a reference to the table name comes up with the HTML and XML data frames as, for example, NULL.Title and books.Title respectively. HTML wasn’t given a table name, explaining the null. The XML data was wrapped in a tag before each object. This is a relatively superficial difference as the dataframe headers can be changed using the “rename” function.The data itself is structured identically.