3rd Lecture

3rd Lecture

.Arithmetic Data Types

.A datatype specifies that what kind of value a variable can store and what are valid operations for declared variable.Datatype reserve memory for variable.

.Data Type Size(Bytes) Conversion

Byte 1 Convert.ToByte (+)

Short 2 Convert.ToInt16 (+/-)

UShort 2 Convert.ToUInt16 (+)

Int 4 Convert.ToInt32 (+/-)

UInt 4 Convert.ToUInt32 (+)

Long 8 Convert.ToInt64 (+/-)

ULong 8 Convert.ToUInt64 (+)

Float 4 Convert.ToSingle Decimal value

Double 8 Convert.ToDouble Double

Precision

Decimal value

char 2 Convert.Tochar

String 2Bytes Convert.Tostring

per character

DataTime 8 Convert.ToDataTime

SByte 2 Convert.ToSByte (+/-)

.There are two types of Datatypes

.Value Type

.Reference Type

List Box:-this control is used to provide a scrollable list of options. User can select single or multiple items.

Select list box> Properties > Items(Collection).

ComboBox:- Defines a drop down list of options. User can select only one item from the combobox. It can be used for selection as well as for typing.

Assignment:-

form 1

.only close with title login

.user id textbox

.password textbox Password Does't Appear to the user. For this choose properties Either passwordchar(for showing character) or usesystemPasswordchar

(for boolean properties).

.button named cancel

.button named Sign In

.if user id and password are wrong than there should be a message contains a title and only 'ok' button otherwise there should be a main form again which contains

4 buttons

>first button named click to open the form list

>second button named comboBox to open form comboBox

>third button named COPY to Open a form containing a list box on left side and one on the left side containing names of cricket teams and in middle there should be 2 buttons

and when be select upper button than the item from the left box move to the right box and maximum items on right side should be 4 and second button for from right to left

and if we want to store more than 4 items than there should be a error message.

>Fourth Button is close button containing a confirmation form either to close or not.

Form 2

on example of list box

.if on clicking bbutton there is nothing written in the text box than there should be a proper message.

.if on clicking delete there is nothing selected than display a appropriate message.

.if delete on all delete button than there should be a confirmation boxwhich ask whether to delegte or not.

Form 3

.a combobox contains name of colleges

.a list box

.when we select a college than list box contains the students of that college

properties of combobox

.dropdown style