Assignment

Description

Assigns values to variables or object properties or object references to object variables.

Syntax

variablename  = expression

Argument

Description

variablename

The name of the variable or object property to which you want to assign a value. Variablename can include dot notation to qualify the variable with one or more object names.

expression

An expression whose datatype is compatible with variablename.

Usage

Use assignment statements to assign values to variables. To assign a value to a variable anywhere in a script, use the equal sign (=). For example:

String1 = "Part is out of stock"

TaxRate = .05


No multiple assignments

Since the equal sign is also a logical operator, you cannot assign more than one variable in a single statement. For example, the following statement does not assign the value 0 to A and B:

A=B=0    // This will not assign 0 to A and B.

This statement first evaluates B=0 to true or FALSE and then tries to assign this boolean value to A. When A is not a boolean variable, this line produces an error when compiled.


Assigning array values

You can assign multiple array values with one statement, such as:

int Arr[]

Arr = {1, 2, 3, 4}

You can also copy array contents. For example, this statement copies the contents of Arr2 into array Arr1:

Arr1 = Arr2


Operator shortcuts

The PowerScript shortcuts for assigning values to variables in the following table have slight performance advantages over their equivalents.

Table 7-1: Shortcuts for assigning values

Assignment

Example

Equivalent to

++

i ++

i = i + 1

--

i --

i = i - 1

+=

i += 3

i = i + 3

-=

i -= 3

i = i -3

*=

i *= 3

i = i * 3

/=

i /= 3

i = i / 3

^=

i ^=3

i = i ^ 3

Unless you have prohibited the use of dashes in variable names, you must leave a space before -- and -=. If you do not, PowerScript reads the minus sign as part of a variable name. For more information, see “Identifier names”.

Examples

Example 1

Example 1 These statements each assign a value to the variable ld_date:

date ld_date

ld_date = Today( )

ld_date = 2006-01-01

ld_date = Date("January 1, 2006")

Example 2

Example 2 These statements assign the parent of the current control to a window variable:

window lw_current_window

lw_current_window = Parent

Example 3

Example 3 This statement makes a CheckBox invisible:

cbk_on.Visible = FALSE

Example 4

Example 4 This statement is not an assignment—it tests the value of the string in the SingleLineEdit sle_emp:

IF sle_emp.Text = "N" THEN Open(win_1)

Example 5

Example 5 These statements concatenate two strings and assign the value to the string Text1:

string Text1

Text1 = sle_emp.Text+".DAT"

Example 6

Example 6 These assignments use operator shortcuts:

Example 7

int i = 4

i ++    // i is now 5.

i --    // i is 4 again.

i += 10  // i is now 14.

i /= 2   // i is now 7.

Example 8

These shortcuts can be used only in pure assignment statements. They cannot be used with other operators in a statement. For example, the following is invalid:

int i, j

i = 12

j = i ++   // INVALID

Example 9

The following is valid, because ++ is used by itself in the assignment:

int i, j

i = 12

i ++

j = i