The largest integer (whole number) that can be held completely accurately is **1** less than **32 2s multiplied together (or 4,294,967,295)** – in other words: *2³²-1* The string "" with no characters at all is called the *empty* or *null* string. Remember that spaces are significant and an empty string is not the same as one containing nothing but spaces. Try: ``` PRINT "Have you finished "Finne gans Wake" yet?" ``` When you press **ENTER**, you will get the flashing red cursor mark that shows there is a mistake somewhere in the line. When the computer finds the double quotes at the beginning of "**Finnegans Wake**", it imagines that these mark the end of the string "**Have you finished** ", and it then can't work out what **Finnegans Wake** means. There is a special device to get over this; whenever you want to write a string quote symbol in the middle of a string, you must write it twice, like this: ``` PRINT "Have you finished ""Finn egans Wake"" yet?" ``` As you can see from what is printed on the screen, each double quote is only really there once; you just have to type it twice to get it recognised. ### Decimal, Binary and Hexadecimal numbers Number literals in *NextBASIC* can be expressed in *Decimal* (default), *Binary* (preceded by **@**) and *Hexadecimal* (preceded by **$**). In the case of integer only literals, the same rule as any with other integer expression applies to binary and hexadecimal literals; they need to be preceded by **%**, *once* per expression. Consider these examples: ``` PRINT %$E3, @11100011 PRINT $E3, %@11100011 PRINT %$E3+@11100011 PRINT $E3+%@11100011 ``` The first example prints an integer and then a floating point number autoconverted from hexadecimal and binary respectively. The same thing happens in the second case but with the first value being a floating point one and the second an integer as again there are two separate expressions following the **PRINT** keyword. The third example is also valid as it contains a properly marked (preceded by **%**) integer expression. The addition of the hexadecimal and binary numbers is a single integer expression as the **%** preceding the addition marked both numbers as integer (and therefore it doesn't need a second **%)**. The fourth example however is NOT valid as it's trying to add a floating point number with an integer number and this expression will fail. In the case of floating point literals, both hexadecimal and binary numbers can have fractional parts. For example:

BIN 1.1	is the same as 1.5 (decimal)
@10.01	is the same as 2.25 (decimal)
$64.c	is the same as 100.75 (decimal)

### More about Integer Expressions and Variables As previously mentioned, the main two reasons for the use of Integer Variables, Arrays and Expressions, is memory efficiency and speed of execution.