Standard datatypes
The datatypes
The standard datatypes in PowerBuilder are the familiar datatypes
that are used in many programming languages, including char, integer,
decimal, long, and string. In PowerScript, you use these datatypes
to declare variables or arrays.
These are the standard PowerScript datatypes, followed by
a description of each:
Blob
Binary large object. Used to store an unbounded amount of
data (for example, generic binary, image, or large text such as
a word-processing document).
Boolean
Contains true or false.
Byte
8-bit unsigned integers, from 0 to +255.
Using literals
To assign a literal value, use any whole positive number in
the range 0 to 255. The leading plus sign is not required (18 and +18
are the same). For example:
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1 |
1        123       200       +55       +200 |
Char or character
A single Unicode character.
If you have character-based data that you will want to parse
in an application, you might want to define it as an array of type char.
Parsing a char array is easier and faster than
parsing strings. If you will be passing character-based data
to external functions, you might want to use char arrays
instead of strings.
For more information about passing character-based
data to external functions, see Application Techniques.
For information about datatype conversion when assigning strings to chars and
vice versa, see “String and char datatypes
in PowerBuilder”.
Using literals
To assign a literal value, enclose the character in either
single or double quotation marks. For example:
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1 |
char c |
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c = 'T' |
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c = "T" |
Date
The date, including the full year (1000 to 3000), the number
of the month (01 to 12), and the day (01 to 31).
Using literals
To assign a literal value, separate the year, month, and day with
hyphens. For example:
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1 |
2001-12-25 // December 25, 2001 |
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2003-02-06 // February 6, 2003 |
DateTime
The date and time in a single datatype, used only for reading
and writing DateTime values from and to a database.
To convert DateTime values to datatypes that
you can use in PowerBuilder, use:
-
The Date(datetime)
function to convert a DateTime value to a PowerBuilder
date value after reading from a database -
The Time(datetime)
function to convert a DateTime value to a PowerBuilder
time value after reading from a database -
The DateTime (date, time)
function to convert a date and (optional) time to a DateTime before
writing to a DateTime column in a database.
PowerBuilder supports microseconds in the database interface
for any DBMS that supports microseconds.
Decimal or Dec
Signed decimal numbers, positive or negative, with up to 28
digits. You can place the decimal point anywhere within the 28 digits—for
example, 123.456, 0.000000000000000000000001 or 12345678901234.5678901234.
Using literals
To assign a literal value, use any
number with a decimal point and no exponent. The plus sign is optional
(95 and +95 are the same). For numbers between zero and
one, the zero to the left of the decimal point is optional (for
example, 0.1 and .1 are the same). For whole numbers, zeros to the
right of the decimal point are optional (32.00, 32.0, and 32. are
all the same). For example:
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1 |
12.34    0.005     14.0    -6500     +3.5555 |
Double
A signed floating-point number with 15 digits of precision
and a range from 2.2250738585073E-308 to 1.79769313486231E+308,
and –2.2250738585073E-308 to –1.79769313486231E+308.
Integer or Int
16-bit signed integers, from -32768 to +32767.
Using literals
To assign a literal value, use any whole number (positive, negative,
or zero). The leading plus sign is optional (18 and +18
are the same). For example:
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1 |
1        123       1200       +55       -32 |
Long
32-bit signed integers, from -2147483648 to +2147483647.
Using literals
Use literals as for integers, but longer numbers are permitted.
LongLong
64-bit signed integers, from -9223372036854775808 to 9223372036854775807.
Using literals
Use literals as for integers, but longer numbers are permitted.
Real
A signed floating-point number with six digits of precision
and a range from 3.402822E-38 to 3.402822E+38, and -3.402822E-38
to -3.402822E+38.
Using literals
To assign a literal value, use a decimal value, followed by
E, followed by an integer; no spaces are allowed. The decimal number
before the E follows all the conventions specified above for decimal
literals. The leading plus sign in the exponent (the integer following
the E) is optional (3E5 and 3E+5 are the same). For example:
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2E4        2.5E38   +6.02E3    -4.1E-2 |
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-7.45E16   7.7E+8   3.2E-38 |
String
Any string of Unicode characters with variable length (0 to
1073741823).
Most of the character-based data in your application, such
as names, addresses, and so on, will be defined as strings. PowerScript
provides many functions that you can use to manipulate strings,
such as a function to convert characters in a string to uppercase
and functions to remove leading and trailing blanks.
For more information about passing character-based
data to external functions, see Application Techniques.
For information about datatype conversion when assigning strings
to chars and vice versa, see “String and char datatypes
in PowerBuilder”.
Using literals
To assign a literal value, enclose as many as 1024 characters in
either single or double quotes, including a string of zero length
or an empty string. For example:
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string s1 |
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s1 = 'This is a string' |
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s1 = "This is a string" |
You can embed a quotation mark in a string literal if you
enclose the literal with the other quotation mark. For example,
the following statements result in the string Here's:
a string
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string s1 |
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s1 = "Here's a string." |
You can also use a tilde (~) to embed a quotation mark in
a string literal. For example:
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string s1 = 'He said, "It~'s good!"' |
Complex nesting
When you nest a string within a string that is nested in another
string, you can use tildes to tell the parser how to interpret the
quotation marks. Each pass through the parser strips away the outermost
quotes and interprets the character after each tilde as a literal.
Two tildes become one tilde, and tilde-quote becomes the quote alone.
Example 1
This string has two levels of nesting:
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"He said ~"she said ~~~"Hi ~~~" ~" " |
The first pass results in:
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He said "she said ~"Hi ~" " |
The second pass results in:
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she said "Hi" |
The third pass results in:
|
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Hi |
Example 2
A more probable example is a string for the Modify function
that sets a DataWindow® property.
The argument string often requires complex quotation marks (because
you must specify one or more levels of nested strings). To understand
the quotation marks, consider how PowerBuilder will parse the string.
The following string is a possible argument for the Modify function;
it mixes single and double quotes to reduce the number of tildes:
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"bitmap_1.Invert='0~tIf(empstatus=~~'A~~',0,1)'" |
The double quotes tell PowerBuilder to interpret the argument
as a string. It contains the expression being assigned to the Invert
property, which is also a string, so it must be quoted. The expression
itself includes a nested string, the quoted A. First, PowerBuilder
evaluates the argument for Modify and assigns the
single-quoted string to the Invert property. In this pass through
the string, it converts two tildes to one. The string assigned to
Invert becomes:
|
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'0[tab]If(empstatus=~'A~',0,1)' |
Finally, PowerBuilder evaluates the property’s expression,
converting tilde–quote to quote, and sets the bitmap’s
colors accordingly.
Example 3
There are many ways to specify quotation marks for a particular set
of nested strings. The following expressions for the Modify function
all have the same end result:
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"emp.Color = ~"0~tIf(stat=~~~"a~~~",255,16711680)~"" |
|
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"emp.Color = ~"0~tIf(stat=~~'a~~',255,16711680)~"" |
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"emp.Color = '0~tIf(stat=~~'a~~',255,16711680)'" |
|
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"emp.Color = ~"0~tIf(stat='a',255,16711680)~"" |
Rules for quotation marks and tildes
When nesting quoted strings, the following rules of thumb
might help:
-
A
tilde tells the parser that the next character should be taken as
a literal, not a string terminator -
Pairs of single quotes ( ‘ ) can be used
in place of pairs of tilde double quotes (~”) -
Pairs of tilde tilde single quotes (~~
')
can be used in place of pairs of triple tilde double quotes (~~~”)
Time
The time in 24-hour format, including the hour (00 to 23),
minute (00 to 59), second (00 to 59), and fraction of second (up
to six digits), with a range from 00:00:00 to 23:59:59.999999.
PowerBuilder supports microseconds in the database interface
for any DBMS that supports microseconds.
Using literals
The time in 24-hour format, including the hour (00 to 23), minute
(00 to 59), second (00 to 59), and fraction of second (up to six
digits), with a range from 00:00:00 to 23:59:59.999999. You separate
parts of the time with colons—except for the fractions
of seconds, which should be separated by a decimal point. For example:
|
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21:09:15 // 15 seconds after 9:09 pm |
|
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06:00:00 // Exactly 6 am |
|
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10:29:59 // 1 second before 10:30 am |
|
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10:29:59.9 // 1/10 sec before 10:30 am |
UnsignedInteger, UnsignedInt,
or UInt
16-bit unsigned integers, from 0 to 65535.
UnsignedLong or ULong
32-bit unsigned integers, from 0 to 4294967295.