Introduction to File Input/output (LOAD and SAVE):

In most cases, the input to a script will come from a data file which has been generated by the other source. It is also useful to be capable to store the output in an external file which can be manipulated and/or printed later. In this part we will elaborate how to read from an external data file, and also how to write an external data file.

There are principally 3 different operations, or modes, on files. The files can be:

• Read from
• Written to
• Appended to

Writing in a file means that writing to a file, from the starting. Appending to a file is also writing, but beginning at the end of the file instead of the beginning. In another words, appending to a file means adding to what was already there.

There are many various file types that use various filename extensions. Now, we will keep it easy and just work with .dat or .txt files when working with data or text files. There are few methods for reading from files and writing to files; for now we will use the load function to read and the save the function to write to files.