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fb_variables [2022/12/03 05:58] – [VAR] praetorfb_variables [2022/12/04 01:39] (current) – [CONST] praetor
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 </code> </code>
  
-Before a variable can be used, it must be **declared**. FreeBASIC provides several ways of declaring variables, but we will focus on <code>DIM</code> and <code>VAR</code> variables.+Before a variable can be used, it must be **declared**. FreeBASIC provides several ways of declaring variables, but we will focus on <code>DIM</code>, <code>VAR</code> and <code>CONST</code> variables.
  
 ==== DIM ==== ==== DIM ====
 The **keyword** DIM is the variable declaration you will use the most in FreeBASIC. With DIM, you are required to declare what sort of data the variable will hold. For instance: The **keyword** DIM is the variable declaration you will use the most in FreeBASIC. With DIM, you are required to declare what sort of data the variable will hold. For instance:
  
-<code> +<code freebasic> 
-dim name as string +dim as string personName 
-dim age as integer +dim as integer personAge 
-dim radius as float+dim as single radius
  
 dim as integer x,y dim as integer x,y
 </code> </code>
- 
-**PITFALL** 
-While it may seem that 
-<code> 
-dim x,y as integer 
-</code> 
-will work, it will in fact cause a compile time error. 
  
 ==== VAR ==== ==== VAR ====
 The second way to declare a variable is use of the keyword //VAR//. Unlike DIM, VAR does not require the type of data to be declared. While this may seem convenient, it comes with some trade-offs. For instance when mixing types. DIM also places everything into an array, which could be thought of as an ice tray with each cubby holding a bit of information. We'll discuss arrays in a later chapter. The second way to declare a variable is use of the keyword //VAR//. Unlike DIM, VAR does not require the type of data to be declared. While this may seem convenient, it comes with some trade-offs. For instance when mixing types. DIM also places everything into an array, which could be thought of as an ice tray with each cubby holding a bit of information. We'll discuss arrays in a later chapter.
 +
 +==== CONST ====
 +CONST variables are constants, that is their assigned value does not change. An example would be
 +<code freebasic>
 +const as single pi = 3.14
 +</code>
  
 === Types === === Types ===
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 ^ Variable types ^ ^ Variable types ^
 | integers | Any whole number that is neither a decimal nor a fraction | | integers | Any whole number that is neither a decimal nor a fraction |
-| float | Any number with a decimal place |+| single | Any number with a decimal place (single precision) |
 | string | A string of characters | | string | A string of characters |
  
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 First, open up your preferred text editor and enter the following statement First, open up your preferred text editor and enter the following statement
  
-<code> +<code freebasic> 
-dim a as integer +dim as integer a 
-dim b as integer +dim as integer b 
-dim c as integer+dim as integer c
  
 a = 5 a = 5
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 First First
-<code> +<code freebasic> 
-dim a as integer +dim as integer a 
-dim b as integer +dim as integer b 
-dim c as integer+dim as integer c
 </code> </code>
 declares 3 variables of the integer type. declares 3 variables of the integer type.
  
-<code>+<code freebasic>
 a = 5 a = 5
 b = 4 b = 4
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 assigns values to our 3 variables and assigns values to our 3 variables and
  
-<code>+<code freebasic>
 print "The number is " & c print "The number is " & c
 </code> </code>
fb_variables.1670047109.txt.gz · Last modified: 2022/12/03 05:58 by praetor