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Visual Basic variables

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Introduction

Comparison of features used in program In Visual Basic variables are declared using Dim and then the name of the variable, which could be anything of your choice. Dim is short for DIMENSION. A Dim statement tells the computer to set up a place in the memory with the right dimensions to store a piece of data that has a certain data type. For example: Dim k As Integer Dim k As Integer sets up a place (location in memory) with the name k and enough space to hold a whole number. "k" is a variable because the values that this location have can vary. As well as setting up the right size of space for a variable, a Dim statement sets up all the things that can be done with the variable according to its data type. In this case Dim statement sets up all the things that can be done with a whole numbers. In Pascal the variables are declared using VAR instead of using Dim. ...read more.

Middle

Character: These are also used the same way in nearly all the languages and are set of symbols that may be represented by a computer at a particular time. These symbols are called characters and can be letters, digits, spaces, and punctuation marks and include non-printing, control characters. Boolean: can only have one of two values, true or false. This makes it easy to use the values of Boolean variables to control the flow of the program. Pointers: is the address or reference of a data element, which allows it to be retrieved without further searching. Pointers allow fast access to data because little searching is required. When used on the data stored in the computer's memory the pointer is usually the address of the data in the memory. However in a database system the pointer may be the primary key or the reference number of the related record. These are basically used to point towards a particular place, for example: Set rng= AciveSheet.Rows (1) This basically point towards the first row of the active sheet. ...read more.

Conclusion

As Range Dim I As Integer For I = 1 To 10 This example of array is basically a variable which is a collection of variable that use the same name, but are distinguished by the index value. In Pascal it would be written differently for example: VAR RANKS:ARRAY [0..51] OF INTEGER; SUITS:ARRAY [0..51] OF CHAR; I:INTEGER; This basically define the variables to store 52 integers. As you can see that they are declared differently in both of the programs Record: is a basic unit of data stored in a datafile. It is a collection of items, which may be of different data types, all relating to the individual or object the record describes and is treated as a unit for processing. Most datafiles contain records, which have the same types of information but about different individuals or objects. File: is a collection of related data. It is traditional to think of files as being structured as a collection of identically structured records mad up of fields Concatenation: this mainly used to join things up Program Routines These are part of the program to do a specific task. It may be a section of the main program or might be formalised as a procedure, function or subroutine ...read more.

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