CSC142

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All data used by a program is stored in
the memory of the computer (numbers, names).
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Location 4 contains 0.981 Location 2
contains the letter c
In a program do not use the location number
(address) explicitly dont want to say
take the content of box
4 would drive us crazy!
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VB.NET strictly enforces the rule. By default it
has Option Explicit on. Dont turn it off! It is
also a good idea to turn Option Strict on to
prevent accidental conversions between types (see
later).
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Many different types some examples
An integer can be 1, -46, 236 (NOT 1.5, -2.3)
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To make your code easier to understand, use the
following stylistic guidelines
_ precede the name of every variable,
constants, or object with a lowercase prefix
specifying the data type. (Hungarian notation
see list p 99)
_ Capitalize each first letter of each word of
a name, e.g. intNumberOfChildren
_ use letters, numbers strEmployee1SSN
_ cant start with a number or underscore
_bad,
1_not_good _ Names cant contain spaces or
periods
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_cant be a VB.NET keyword
End, Dim, As ...
_NOT case sensitive temperature is the
same as Temperature
_ length practically, as long as you want
(the limit is 16,383 characters, but...)
_ meaningful names Dim intAge As Integer
NOT Dim a As Integer
VB will help you as you type...
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Within a program, some values do not
change e.g. value of pi 3.14159
To avoid any accidental change, declare such
values as constants
Const dblPI As Double 3.14159
VB provides a set of built in constants.
(intrinsic constants). You need to specify
class name and constant name, e.g. Color.Red
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We have seen String, Integer, Double
Also
Uses lots of memory, not as efficient. Avoid if
you can
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Declare a variable
We get a box. But how to put something in it?
Or better said How to store the value of
a variable in the memory?
Dim strName As String strName "Jane Beckmann"
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Consider dblPerimeter
dblPIdblDiameter
Note can have intYear intYear 1
(NOT a mathematical equation!)