Glossary TOC

The gloss of the Web

was lost on the fly

who intended to miss it

as he passed by

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• abstract An abstract class or method.
  
  

• boolean The boolean type ( a logic valued data type)
  
  

• bit and byte A bit is a single binary value in a list of binary values ( i.e 1001 includes four bits) while a byte is a set of eight bits or 256 pieces of information (i.e. 1001 1101 is a byte).
  
  

• byte integer data type (1 byte) -128 to 127.
  
  

• browser refers to a computer program which allows the user to access the information over the internet in a simple and easy way. By browser we will typically mean an http type browser which allows for the transfer of graphics and convenient viewing of text.
  
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• case switch/case - control structure with ability to choose different paths e.g. assume that choice is an integer 1,2 ,3,...
  
  switch(choice)
    { case 1: ...
      break;
      case 2: ...
      break;
...
      default:...
      break;
    }
  
  
• cast is a process in which one data type is recast to another relatively compatible data type. E.g.
  
  double realnum=0.5;
int i;
...
i = (int) realnum;

  "realnum" is recast as an integer so that the value of "i" may be set.
  

• catch Error detection and correction structure which allows the programmer to catch an exception which could otherwise dump the program. E.g.
  
  
          public Object clone(){ //begin clone
            try{ //begin try
            return super.clone();
                } //end try
  
        catch(CloneNotSupportedException e){ // begin catch
            return null; //if there is a catch
            } //end catch
            } //end cloning structure for point
  
  
  
  

• char The unicode character type - allows the programmer to use a single character but not as a string .
  
  

• class Defines a class type. A class is the terminonolgy generally used for a programming object. This is also used as a suffix on machine coded objects , methods and executable programs
  
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• do part of the do/while loop control structure e.g.
  
  a= 1;
b = 0;
do
  { a = a+ 1;
    b = b+2;
  }
while (a < 10) ; // for a =9 or less continue
  
  
  
• double double precision floating point data type.
  
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• else Used as a control structure in an if statement - see also if.
  
  

• extends Used by a progeny class to indicate the parent class. The progeny then inherits the properties and qualities of the parent class.
  
  

• float Single precision floating point.
  
  

• for Beginning of a for loop e.g.
  
  for(i=0;i<11;i++)
          { //begin for loop exectution
          num = num + i;
          count = count + 1;
          } //end for loop execution

  or
  
  for(i=0;(sky="thelimit")&&(moon="bright");i<11;i++)
          { //begin for loop exectution
          num = num + i;
          count = count + 1;
          } //end for loop execution

  note that the for statement can contain many conditions. Observe that the execution statements are framed inside a pair of curly braces{}.
  
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• gif - Graphics Interchange Format - A rigid graphical file description system.
  
  

• Graphical User Interface refers specifically to point and click view screen technology.
  
  

• HTML - HyperText Markup Language- The computer language used to format an webpage. This language is a subset of the language CGML.
  
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• if The beginning of a decision structure e.g.
  
  if(i==j){
num=7;
moon="high";
          } // end if
else if (i==j+1){
num=6;
moon="low";
          } //end else if
else {
num=8;
moon="middle";
          } //end else

  
  

• implements is used in class definitions to invoke other class methods or interfaces within the definition.
  
  public class point implements Cloneable{
          public int x;
          public int y;

        public Object clone(){ //begin clone
          try{ //begin try
          return super.clone();
              } //end try

      catch(CloneNotSupportedException e){ // begin catch
          return null; //if there is a catch
          } //end catch
          } //end cloning structure for point

          } //end point def

  
  
• import calls the given library package to be loaded when needed by the compiler. (e.g.
  
  import java.applet.*
  
  will make the java applet library available during the compilation of the program.)
  
  
• inheritance A feature of object oreiented programming languages. Specifically, it allows extending classes or progeny to use all of the public procedures and variables of the parent class.
  
  
• int is the primitive integer data type. The minimum value is -2147483648 and the maximum value is 2147483647. (e.g.
  
  
• jpeg - Joint Photographic Expert Group - a rigid graphical file description system and file compression scheme which can use millions of colors.
  
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• long - integer data type with range of approximately -10¹⁹ to 10¹⁹.
  
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• method - inclusive term for java defined functions, subroutines etc.. A method is essentially a java object.
  
  
• NaN - Not a Number .
  
  
• mpeg - Moving Pictures Expert Group- A set of ordered graphical files which can produce a moving picture.
  
  
• new - is used to create an instance of a programmer defined object type or to initialize a new variable.
  
  public Employee(String n, double s)
    { name=n;
      salary=s;
    }
    Number007= new Employee("Bond, James Bond", 1000007);

  
  
• null - used to return a null value in a function method.
  
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• object Generic name for classes. In particular in Java an object is a specific instance of a class.
  
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• private - essentially defines an object as local or pertaining to the class.
  
  
• protected - objects available to subclasses etc.
  
  
• public - objects available to the world.
  
  

• Portable A portable program or file system is one that can be used on several different computers without using a converter. The standard system for portable text files is ASCII. Java is an example of a portable programming language.
  
  
• return - the result of a method especially a function method. The return in a method gives the value or values to be returned by the function to the main or subroutine that calls the function. A return is not needed if the method is void.
  
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• short - integer data type (2 bytes) approximately -32,000 to 32,000.
  
  
• static - static fields do not change from one instance of a class to another. Static methods belong to a class and do not operate on any particular instance of the class.
  
  
• subclass - a child of a class
  
  
• super

public Object clone(){ //begin clone
  try{ //begin try
  return super.clone();
      } //end try

catch(CloneNotSupportedException e){ // begin catch
  return null; //if there is a catch
  } //end catch
  } //end cloning structure for point

  } //end point def

  
  

• superclass - the super calss object or constructor, see for instance super.
  
  

• switch
  
  switch(count){ \\begin case checks
      case 2: note="high"; break;
      case 5: note="low"; break;
      case 17: note="out_of_range";break;
      default: note="clear";break;
             } //end case checks

  
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• this - refers to the object on which the method operates.
  
  

• throw - used to detect and handle possible exceptions or error in the program. Suppose you wish to check a string for the correct length. You count the characters as "n", e.g.
  
  { while (...)
    if (ch==-1) //EOF encountered
     { if (n < correctLength)
        throw new EOFException();
     } //end if
    } //endif
} //endwhile
  
  

• true - boolean type.
  
  

• try .
  
  // Read a parameter interpret as hexidecimal and
//convert to color.
protected Color getColorParameter(String name){
String value=this.getParameter(name);
int intvalue;
try{ intvalue=Integer.parseInt(value,16);} // end try
catch(NumberFormatException e){return null;} // end catch

return new Color(intvalue);
} // end get Color

  
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• UNIX The UNIX operating system originally grew out of the the MULTICS operating system developed for a General Electric computer system. This was the product of a consortium of computer related industries. When the consortium failed to produce a satisfactory product, a computer operating system was developed on a PDP-7 at Bell Labs by Ken Thompson, one of the participants in the original MULTICS project. Ironically, it was dubbed UNIX because it actually could handle multitasking effectively. UNIX created the open system environments along with security measures that made the internet possible. Many of the file transfer protocols grew out of the UNIX concept.
  
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• void used for methods that are not really functions. No return value is needed.
  
  

• while loop control structure- see also do/while .