Computer Programming Concepts and Visual Basic David I. Schneider

452 Computer Programming Concepts and Visual Basic
TIME The value of the function Time is the current time expressed as a string of the form
hh:mm:ss. (The hours range from 0 to 23, as in military time.) If timeStr is such a string, the
statement Time = timeStr sets the computer’s internal clock to the corresponding time.
TIMER The value of the function Timer is the number of seconds from midnight to the time
currently stored in the computer’s internal clock.
TIMER The Timer event is triggered by the passage of the amount of time specified by the
Interval property of a timer control whose Enabled property is set to True.
TIMESERIAL The value of the function TimeSerial(hour, minute, second) is the serial date
corresponding to the given hour, minute, and second. Values from 0 (midnight) to 23 (11
p.m.) for hour, and 0 to 59 for both minute and second are normal, but any Integer value may
be used. Often, numeric expressions are used for hour, minute, or second that evaluate to
numbers outside these ranges. For example, TimeSerial(15–5, 20–30, 0) is the serial time 5
hours and 30 minutes before 3:20 p.m.
TIMEVALUE The value of the function TimeValue(str) is the serial date corresponding to
the time given in str. TimeValue recognizes both the 24-hour and 12-hour time formats:
“13:45:24”or “1:45:24PM”.
TOP The property Top determines the position of the top edge of a form or control. The units
of measure are twips for forms. The units of measure for a control are determined by the
ScaleMode property of the container (form, picture box, etc.) on which the control has been
placed, with the position of the control measure from the edge of its container using the coordinate
system established by the various Scale... properties for the container. By default, the
unit of measure for a container is twips, with a value of 0 for the Top property placing the
control against the top edge of the container.
TRIM The value of the function Trim(str) is the string obtained by removing all the spaces
from the beginning and end of the string str. The string str may be either fixed-length or variable-length.
TRUE A keyword of the Boolean type. True is used when setting the value of properties that
are either True or False. For example, Picture1.Font.Italic = True.
TYPE/END TYPE A multistatement block beginning the Type typeName and ending with
End Type creates a user-defined record type. Each statement inside the block has the form
elt As type, where elt is a variable and type is either Integer, Boolean, Byte, Date, Long, Single,
Double, Currency, Variant, String*n (that is, fixed-length string), or another user-defined
record type. After a statement of the form Dim var As typeName appears, the element corresponding
to the statement elt As type is referred to as var.elt. Type declaration blocks must
be placed in the (Declarations) section of a BAS module. [variant]
TYPENAME If var is variable, then the value of the function TypeName(var) is a string
identifying the type of the variable. The possible values of the function are Byte, Integer,
Long, Single, Double, Currency, Date, String, Boolean, Error, Empty (uninitialized), Null
(no valid data), Object (an object that supports OLE Automation), Unknown (an OLE
Automation object whose type is unknown), and Nothing (an object variable that doesn’t
refer to an object).
UBOUND For a one-dimensional array arrayName, the value of the function
UBound(arrayName) is the largest subscript value that may be used. For any array array-
Name, the value of the function UBound(arrayName, n) is the largest subscript value that
may be used for the nth subscript of the array. For example, after the statement Dim example(1
To 31, 1 To 12, 1990 To 1999) is executed, the value of UBound(example, 3) is the
largest value allowed for the third subscript of example( ), which is 1999.
UCASE The value of the string function UCase(str) is a string identical to str except that all
lowercase letters are changed to uppercase.