VB .Net Data Type
(A) Numeric Data Types
| Data Type | Memory Size (Bytes) | Empty/Default Value | Value Range |
|---|---|---|---|
|
Short |
2 |
0 (Small Integer) |
|
|
Integer |
4 |
0 (Medium Integer) |
|
|
Long |
8 |
0 (Long Integer) |
|
|
Single |
4 |
0.0 (Small Float ) |
|
|
Double |
8 |
0.0 (Medium Float) |
|
|
Decimal |
16 |
0.0 (Long Float) |
(B) Character and String Data Type
| Data Type | Memory Size (Bytes) | Empty/Default Value | Value Range |
|
Char |
2 |
stores only single character enclosed between double quotation mark. |
|
|
String |
Up to 2 billion characters |
stores textual information as letters, digit and some special characters/combination of all these and enclosed between double quotation mark. |
(C) Byte Data Type
| Data Type | Memory Occupied (Bytes) | Default Value | Value Range |
|
Byte |
1 |
0 ( Byte data type is used to store binary data such as binary file, image, sound etc… It is unsigned Byte data type) |
|
|
SByte |
1 |
0 (stores binary data such as binary file, image, sound etc…It is signed Byte data type. ) |
(D) Boolean Data Type
| Data Type | Memory Occupied (Bytes) | Default Value | Value Range |
|
Boolean |
2 (stores true or false value. we can also assign integer value to Boolean variable. Any Non-Zero value is considered as TRUE and zero is considered as FALSE.) |
FALSE |
stores true or false value. we can also assign integer value to Boolean variable. Any Non-Zero value is considered as TRUE and zero is considered as FALSE. |
(E) Date Data Type
| Data Type | Memory Occupied (Bytes) | Default Value | Value Range |
|
Date |
8 |
Date datatype is used to store Date and Time value. |
(F) Object Data Type
| DataType | Memory Occupied (Bytes) | Default Values | Value Ranges |
|
Object |
8 |
It is the default type of the variable. It means if you don’t declare the variable then the default Data Type for that variable is object. |
stores value of any data type. |
The Regular Expression Pattern Meaning
The regular expression pattern ^(?(")(".+?(?<!\\)"@)|(([0-9a-z]((\.(?!\.))|[-!#\$%&'\*\+/=\?\^`{}|~\w])*)(?<=[0-9a-z])@))(?([)([(\d{1,3}.){3}\d{1,3}])|(([0-9a-z][-0-9a-z]*[0-9a-z]*.)+[a-z0-9][-a-z0-9]{0,22}[a-z0-9]))$ is interpreted as shown in the following table.
| Pattern | Description |
|---|---|
^ |
Begin the match at the start of the string. |
(?(") |
Determine whether the first character is a quotation mark. (?(") is the beginning of an alternation construct. |
(?("")("".+?(?<!\\)""@) |
If the first character is a quotation mark, match a beginning quotation mark followed by at least one occurrence of any character, followed by an ending quotation mark. The ending quotation mark must not be preceded by a backslash character (\). (?<! is the beginning of a zero-width negative lookbehind assertion. The string should conclude with an at sign (@). |
|(([0-9a-z] |
If the first character is not a quotation mark, match any alphabetic character from a to z or A to Z (the comparison is case insensitive), or any numeric character from 0 to 9. |
(\.(?!\.)) |
If the next character is a period, match it. If it is not a period, look ahead to the next character and continue the match. (?!\.) is a zero-width negative lookahead assertion that prevents two consecutive periods from appearing in the local part of an email address. |
|[-!#$%&'*+/=?^`{}|~\w] |
If the next character is not a period, match any word character or one of the following characters: -!#$%’*+=?^`{}|~. |
((.(?!.))|[-!#$%'*+/=?^`{}|~\w])* |
Match the alternation pattern (a period followed by a non-period, or one of a number of characters) zero or more times. |
@ |
Match the @ character. |
(?<=[0-9a-z]) |
Continue the match if the character that precedes the @ character is A through Z, a through z, or 0 through 9. The (?<=[0-9a-z]) construct defines a zero-width positive lookbehind assertion. |
(?(\[) |
Check whether the character that follows @ is an opening bracket. |
(\[(\d{1,3}\.){3}\d{1,3}\]) |
If it is an opening bracket, match the opening bracket followed by an IP address (four sets of one to three digits, with each set separated by a period) and a closing bracket. |
|(([0-9a-z][-0-9a-z][0-9a-z].)+ |
If the character that follows @ is not an opening bracket, match one alphanumeric character with a value of A-Z, a-z, or 0-9, followed by zero or more occurrences of a hyphen, followed by zero or one alphanumeric character with a value of A-Z, a-z, or 0-9, followed by a period. This pattern can be repeated one or more times, and must be followed by the top-level domain name. |
[a-z0-9][\-a-z0-9]{0,22}[a-z0-9])) |
The top-level domain name must begin and end with an alphanumeric character (a-z, A-Z, and 0-9). It can also include from zero to 22 ASCII characters that are either alphanumeric or hyphens. |
$ |
End the match at the end of the string. |
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