Computer Programming Concepts and Visual Basic David I. Schneider

450 Computer Programming Concepts and Visual Basic
SHELL If command is a DOS command, the function Shell(command) causes command to
be executed. If the DOS command requires user input, execution of the Visual Basic program
will be suspended until the user input is supplied. Using the function Shell with no arguments
suspends program execution and invokes a copy of DOS. Entering the command Exit
resumes execution of the Visual Basic program. The value returned by the Shell function is
a number used by Windows to identify the new task being performed.
SHOW The Show method makes an invisible form visible. The statement Form1.Show 1 also
makes a form modal. No user input to any other form will be accepted until the modal form
is hidden.
SIN For any number x, the value of the trigonometric function Sin(x) is the sine of the angle
of x radians. [radians]
SINGLE A variable of type Single requires 4 bytes of memory and can hold 0, the numbers
from 1.40129×10 –45 to 3.40283×1038 with at most seven significant digits, and the negatives
of these numbers. Single values and variables may be indicated by the type tag !: 32.156!,
Meters!.
SMALLCHANGE When a scroll bar arrow button is clicked, the Value property of the scroll
bar changes by the value of the SmallChange property and the thumb moves accordingly.
SORTED When the Sorted property of a list or combo box is set to True, the items are automatically
presented in alphabetical order.
SPACE If n is an integer from 0 to 32767, the value of the function Space(n) is the string
consisting of n spaces.
SPC The function Spc is used in Print and Print# statements to generate spaces. For instance,
the statement Print str1; Spc(n); str2 skips n spaces between the displays of the two strings.
SQR For any nonnegative number x, the value of the square root function Sqr(x) is the nonnegative
number whose square is x.
STATIC A statement of the form Static var1, var2, .20.20. can be used at the beginning of
the definition of a procedure to specify that the variables var1, var2, .20.20. are static local
variables in the procedure. Memory for static variables is permanently set aside by Visual
Basic, allowing static variables to retain their values between successive calls of the procedure.
The type of each variable is either determined by a DefType statement, a type-declaration
tag, or an As clause. Static variables have no connection to variables of the same name
outside the procedure, and so may be named without regard to “outside” variables. Arrays
created in a procedure by Dim or ReDim are lost when the procedure is exited. Arrays that
are local to a procedure yet retained from one invocation of the procedure to the next can be
created by dimensioning the array in the procedure with a Static statement rather than a Dim
or ReDim statement. Dimensions for static arrays must be numeric constants. A local static
array whose size is to be determined at run time is declared by listing its name followed by
empty parentheses in a Static statement, and then dimensioning the array in a subsequent
ReDim statement.
STOP The statement Stop suspends the execution of a program. Execution can be resumed
beginning with the first statement after the Stop statement by pressing F5.
STR The Str function converts numbers to strings. The value of the function Str(n) is the
string consisting of the number n in the form normally displayed by a print statement.
STRCOMP The value of the function StrComp(str1, str2, compMode) is –1, 0, 1, or Null,
depending on whether str1 < str2, str1 = str2, str1 > str2, or either of str1 and str2 is Null. The
comparison will be case-sensitive if compMode is 0 and case-insensitive if compMode is 1.
STRCONV The value of StrConv(str, 3) is the value of str with the first letter of every word
converted to uppercase. The value of StrConv(str, 1) is the same as UCase(str) and the value
of StrConv(str, 2) is the same as LCase(str).