Components in Computer Languages

• Variables -Variables is a simple concept that can provide a very powerful mechanism for creating more interesting game play. A variable is just a place for storing some kind of information, such as a number or some text. Certain properties we can set when we define an object, such as whether it is visible or solid. Other properties store information that is different for each individual instance, such as its x- and y -position in the room. For example, each plane in a room has a different x and y coordinate. There are also a number of global variables, like score, or lives that are not related to an individual instance of an object. Each variable has its own unique name, which can be used to retrieve or change the value of that variable. This definition is from the "The Game Maker's Apprentice, Game development for Beginners book (the brown book) by Jacob and Mark Overmars. (pg 170 - 171.)
  • In computer programming, a variable is a symbolic name given to some known or unknown quantity or information, for the purpose of allowing the name to be used independently of the information it represents. A variable name in computer source code is usually associated with a data storage location and thus also its contents, and these may change during the course of program execution.
  • Variables in programming may not directly correspond to the concept of variables in mathematics. The value of a computing variable is not necessarily part of an equation or formula as in mathematics. In computing, a variable may be employed in a repetitive process: assigned a value in one place, then used elsewhere, then reassigned a new value and used again in the same way (see iteration). Variables in computer programming are frequently given long names to make them relatively descriptive of their use, whereas variables in mathematics often have terse, one- or two-character names for brevity in transcription and manipulation.
  • Compilers have to replace variables' symbolic names with the actual locations of the data. While the variable name, type, and location generally remain fixed, the data stored in the location may get altered during program execution. http://en.wikipedia.org/wiki/Variable_%28computer_science%29
  • Variable and Constant definitions in REAL basic http://goldclasses.com/basic/Lessons/DeclarationExercise.htm
    • Variable have Types: for example in REALBasic Integer, String, Boolean; in Java int, char, boolean, double...etc
    • Variable also have Scope: Their scope is local or global. Local means the variable and its' value is temporary, and global the variable is known throughout the entire program. Local variables are usually declared within a block of code. Blocks of code are methods or can be delineated by brackets.
    • Variables can be used as parameters or they can be called arguments. A parameter or an argument is a value that is passed to a method so that the method can use that value in its processing. Parameters/arguments are placed in between a method/function or subrountines via a type within the methods parenthesis. If more parameters are needed they are then followed by a comma more data types and data.
      • Ex: in Java
      • public String getName(String x, int y){
        return "Mr. " + x + " y = " + y;
        }

    http://wiki.answers.com/Q/What_is_parameters_in_java_show_you_example
    

• Arrays and Lists -In programming, a series of objects all of which are the same size and type. Each object in an array is called an array element. For example, you could have an array of integers or an array of characters or an array of anything that has a defined data type. The important characteristics of an array are:
  Each element has the same data type (although they may have different values).

The entire array is stored contiguously in memory (that is, there are no gaps between elements).

Arrays can have more than one dimension. A one-dimensional array is called a vector ; a two-dimensional array is called a matrix. http://www.webopedia.com/TERM/A/array.html

Array Simpsons = ["Homer","Marge","Bart","Lisa","Maggie"]
There are many different kinds and implementations of arrays, but their use in data organization is immeasurable. http://answers.yahoo.com/question/index?qid=20090206085004AAHTOqT

• Statements -In computer programming a statement can be thought of as the smallest standalone element of an ... programming language. http://en.wikipedia.org/wiki/Statement_%28computer_science%29

REALBasic statements end in a new line

Java statements end with a semi-colon

• Conditionals -In computer science, conditional statements, conditional expressions and conditional constructs are features of a programming language which perform different computations or actions depending on whether a programmer-specified boolean condition evaluates to true or false.

• If-then(-else)
• The if-then construct (sometimes called if-then-else) is common across many programming languages. Although the syntax varies quite a bit from language to language, the basic structure (in pseudo code form) looks like this: (The example is actually perfectly valid Visual Basic or Quick BASIC syntax.)
  • If (predicate) -the predicate is a expression that will evaluate to a boolean (true or false)
    Then
    (consequent)
    Else
    (alternative)
    End If

• Loops - In computer programming, conditional loops or repetitive control structures are a way for computer programs to repeat one or more various steps depending on conditions set either by the programmer initially or real-time by the actual program. http://en.wikipedia.org/wiki/Conditional_loop
• Methods/Functions - In object-oriented programming, a method is a subroutine (or procedure or function) associated with a class. Methods define the behavior to be exhibited by instances of the associated class at program run time. Methods have the special property that at runtime, they have access to data stored in an instance of the class (or class instance or class object or object) they are associated with and are thereby able to control the state of the instance.[1] The association between class and method is called binding. A method associated with a class is said to be bound to the class. There are different types of methods in OO programming, Overloaded methods, Abstract methods, and Virtual methods. http://en.wikipedia.org/wiki/Method_%28computer_programming%29
  • "In Game Maker functions are the most important ingredients of a program; they are the things that let Game Maker perform certain tasks. For every ACTION there is a corresponding function, but there are many, many more. In total,, close to a thousand functions are available that deaal with all aspects of you game, such as motion, graphics, sound, and user input." This definition is from the "The Game Maker's Apprentice, Game development for Beginners book (the brown book) by Jacob and Mark Overmars. (pg 230.)
  • In REAL Studio "The Function statement is used to define a method that can be used on the right side of an expression just like the built-in functions such as Abs, Len, etc. All executable code must be in a Sub or Function statement. A Function differs from a Sub in that a Function can be used on the right side of an expression and a Sub cannot. A function cannot be defined inside another Sub or function. A function executes each line of code from the top down. Once the last line of code is executed, control returns to the line that called the function."

• Classes-In object-oriented programming, a class is a construct that is used as a blueprint to create instances of itself – referred to as class instances, class objects, instance objects or simply objects. A class defines constituent members which enable these class instances to have state and behavior. Data field members (member variables or instance variables) enable a class object to maintain state. Other kinds of members, especially methods, enable a class object's behavior. Class instances are of the type of the associated class.

A class usually represents a noun, such as a person, place or (possibly quite abstract) thing, or something nominalized. For example, "Banana" is an instance of the class "Fruit" (a "Fruit" object). It is of the type "Fruit".

http://en.wikipedia.org/wiki/Class_%28computer_programming%29