By default, this range consists of all integer values between the first arg and the second arg. Any other range (eg. smaller or greater steps than 1 or negative steps) can be specified by step's arg.

If you specify elseif, which you can do any number of times within an if ... then ... endif condition, then it will test its expression only of none of the preceding conditions had been tested true.

If you specify else, then the commands after else will be executed only if none of the preceding if and elseif expressions have tested true. 

The on ... gosub command can also have a numeric variable as an index for a list of labels to jump to. E.g. to randomly jump to labels one, two, or three, use on int(ran(3))+1 gosub one, two, thee.

Using this function you can add your own commands to the Yabasic language within your program. Use this for code that you use or reuse often in your programs, for instance for a routine that draws a menu on the screen or receives a certain string of commands from the controller.

Not all arguments need to be specified, and you can check yourself how many arguments have been passed to the subroutine using the system variable numparams. 

With using mask$ you can influence the appearance of numbers. For instance, if you want a value in Euros to be presented according to the EU currency standard (a precision of five digits after the decimal point), you can specify a mask as follows: "##.#####". 

If you want this function to round off a variable (e.g. 6.6 -> 7), then add 0.5 to arg before performing the int() function.

The result is a real number (e.g. 6.3452), so if you only want an integer, then use the int() function as well, e.g. int(ran(19)). 

If you leave out arg, you get a real number between 0 and 1. 

With prompt$ you can provide a prompt for the user (eg. input "What is your name" name$). This supplied string will then replace the "?", which is good - always more fun to have your own prompt.  

Notice that if you set the keyboard to "US", as for instance I do since in the Netherlands we mainly use "US" keyboards, then you will have trouble spotting the key for "|" and "\", as this has been mapped to "<" and ">", and you won't find "|" and "\" anywhere else on the keyboard either (or at least I didn't). 

In "UK" mode, this problem does not exist. I haven't checked the other language settings ("German", "French"). If you find anything interesting, let me know at a.arum@wxs.nl and head the message PS2: Keyboard Layouts.

For instance, the return key is represented by the value 13, the space key is represented by the value 31, and "A" is represented by 65. 

If you want to check the ASCII code of a special key like the return key which you cannot type into a string in your program, then you can also use an escape sequence, as described at the end of this section.

For instance, "A" is 65, and "a" is 97, so chr$(65) returns "A" and chr$(97) returns "a".

For instance, if you would supply a string variable containing a regular English sentence as the first arg$ of the token command, and an array as the second arg$() of the token command, then after the command has executed then arg$() will have become an array containing each of the words in the sentence. 

Optionally, you can supply a third argument with which you can indicate other character(s) at which the token command should split your string. Slices that are empty, for instance as a result of two or more adjacent spaces, are ignored and not put into the array.

Each is separated by a dash ("-") and an easy way of reading these values separately is by using the token and split functions described above with the "-" as a third argument.   

Each is separated by a dash ("-") and an easy way of reading these values separately is by using the token and split functions described above with the "-" as a third argument.    

The backslash, for instance, is part of indicating an escape sequence, and if you use it in a string for a different purpose it will still not display the backslash, but try to interpret an escape sequence. But you just want it to be a backslash, and in order to do so, you must use an escape sequence, namely "\\". 

This command is required before you can execute any of the other graphics output commands. You can also use the open command as an expression, as it returns true or false depending on whether the open command was successfully executed. 

E.g. window origin "lb" sets the window origin to left - bottom. 

Default origin is left - top ("lt").

You can use new curve to indicate you which to start a new line-section, so that there is no line between this and the previous line. 

If you specify clear, you will effectively draw the line in color 0 (the background color), which has the effect of 'clearing' a line. 

If the optional first arg$ is supplied, you can indicate the position of the text in relation to the specified coordinate in a two-character string. The first character indicates the horizontal position (l - left, c - centre, r - right), and the second character indicates the vertical position (t - top, c - centre, b - bottom). 

This can be very useful if you want to write a program that should also run on other operating systems, like Unix or Windows, and you want to test whether or not you can use a particular function that is only supported on that platform, or supported in a limited or extended way.  

This can be very useful if you want to make sure your Yabasic program is running on a version of the Yabasic interpreter that supports the commands you are using in your program.