KonsolScript:Tutorials:Variables

From GPWiki

Variables

Variables help your computer to remember values. Upon closing your program, all values assigned to variables will be forgotten.

Data types

KonsolScript can remember three types of data -- numeric, state, and textual values.

• Number - remembers any numeric value.
• Boolean - remembers any state (or better known to others as flags).
• String - remembers any type of data as textual data.

User-Defined Variables

You can use variable to your program -- You just have to declare one using the syntax below.

/*
 * Var:DataType variable_name;
 */

By following the syntax, we can declare our variable named age.

//declares age as Number variable
  Var:Number age;
  age = 24;

Variable Scope

• Local Variables - these variables are only accessible inside the function it was declared.

function main() {
  foo()
  Konsol:Log("inside main() > " + x)
}
function foo() {
  Var:Number x;
  x = 10;
  Konsol:Log("inside foo() > " + x)
}
//Outputs...
//inside foo() > 10
//Error in line 3 

The sample above makes an error because x was declared inside foo function.

function main() {
  Var:Number x;
  x = 20;
  foo()
  Konsol:Log("inside main() > " + x)
}
function foo() {
  Var:Number x;
  x = 10;
  Konsol:Log("inside foo() > " + x)
}
//Outputs...
//inside foo() > 10
//inside main() > 20 

The sample above makes demonstrates a local variable on two different functions that uses same name would not cause error because neither was declared as global variable.

Var:Number x;
function main() {
  x = 20;
  foo()
  Konsol:Log("inside main() > " + x)
}
function foo() {
  Var:Number x;
  x = 10;
  Konsol:Log("inside foo() > " + x)
}
//Outputs...
//Error on line 8 

The code above shows a conflicting declared Global and Local variable that uses same name. Once a variable was declared globally, it cannot be re-declared inside any function.

• Global Variables - these variables are accessible from any functions that tries to store values to it.

Var:Number x;
function main() {
  x = 20;
  foo()
  Konsol:Log("inside main() > " + x)
}
function foo() {
  x = 10;
  Konsol:Log("inside foo() > " + x)
}
//Outputs...
//inside foo() > 10
//inside main() > 10 

Although main function assigned 20 to x first, foo function will print out 10 since it stored the value 10 after main function did. And so, main function will also print 10.

Built-in Variables

KonsolScript declares some variables to act as the fake Direct Memory Access. For example, you can check if the Left-Mouse Button is pressed by checking the state of LMB (a built-in Boolean variable).

You can see the name of other built-in variables in FreeKE.log (when using FreeKE) or kwkse.log (when using Quixie).

All KonsolScript built-in variables are global variables.

~creek23~