Concatenation

Concatenation is the joining together of pieces of text. In RFO Basic, you can concatenate text using the " +" symbol:

Concatenation is particularly useful when combining static text with data stored in variables or returned by functions. You will use code similar to the following in virtually every program you write:

Since you can't code an unkown user's name into your program, you must use a variable, and concatenate that text with other static (unchanging) text whenever you want to refer to the user's name in your program.

To concatenate text strings on multiple lines, use the tilde character (~):

The " time" function sets all the following return variables to the current year, month, day, hour, minute, and second. Here's a nicely formatted concatened string that displays the current date and time:

Again, since a programmer can't write the user's arbitrary current time into the code, variables and concatenation must be used to retrieve the current time, and refer to it by dynamically generated text.

Some Basic Text Formatting Guidelines

You can include quotes inside strings by prefacing them with the backslash character (\):

Multi-line text uses " \n" to represent a carriage return:

Conditions

Conditions are used to manage program flow... to make " decisions" in your program. They are among the most important concepts in all types of programming.

If

The most basic conditional evaluation is " if":

Math operators are typically used to perform conditional evaluations: = < > < > (equal, less-than, greater-than, not-equal):

The above code could also be written as follows. The hour text is converted to a number, inline: