In JavaScript the Variable are also declared in a similar way to Pascal for example:
Var day=mydate.getDay();
This is the declaring of the variables, you can also assign values to the variables.
Data Types: is a formal description of the kind of data being stored or manipulated within a program or system, for example alphabetic data, numeric data or logical data some of the more important one are listed below.
Number (integer): is any whole number, whether positive or negative. In visual basic you can declare the number as an integer, for example:
Dim bookingNo As Integer
and this is the same in Pascal, for example
VAR I, J: INTEGER;
Number (real): is any number represented with a fractional part. In most high-level languages, real indicates that floating-point representation is to be used when the number is stored or manipulated. This implies that the number may contain a fractional part and that it is processed to a limited number of significant figures.
This is used the same way in nearly all languages and doesn’t need to be declared like an integer.
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.
Data Structures: is a group of related data items organised in a computer. A data structure allows a large number of pieces of data to be managed as a single set. Each type of data structure makes it easy for the programmer to find and process the data in particular ways. Each type of structure has its own strengths and weaknesses. Examples of data structures are arrays, lists, tables, trees, strings and files.
String: is textual data in the form of a list of characters, for example words and punctuation. String data is made up of characters data and will usually vary in length.
String is basically a variable containing text for example:
Var dayarray=new
Array(“Sunday”,“Monday”,“Tuesday”,“Wednesday”,“Thursday”,“Friday”,“Saturday”)
The Var dayarray=new is basically a string containing text which has been declared after that. This could be used later on in the program.
Array: is set of data items of the same type grouped together using a single identifier. Each of the data items is addressed by the variable name and a subscript.
An example of this is:
Dim cell (1 To 10000) 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