Most ESL statements require you to specify one or more values. There are various categories of values, and every value has a type: string (text), integer (ESL integers), float (ESL floating point numbers), or boolean (true or false). Note that only constants and variables have default values.
Values
Category |
Types |
Default |
Examples |
Literal |
String Integer Float Boolean |
false |
"status OK" 5 27.96 |
Constant |
String Integer Float Boolean |
“” 0 0.00 false |
CompanyName Counter_Max Dividend TrueFlag |
Variable |
String Integer Float Boolean |
“” 0 0.00 false |
Password EmployeeNumber Grand_Total FirstTime |
Variable preceded by a unary operator |
Integer Float Boolean |
|
-A -Profit not AlreadyDone |
Parenthesized Expression |
String Integer Float Boolean |
|
(Message = "Final step") (A * B + C) (A * 1.5) ((A > B) and (C > D)) |
Built-in Function |
String Integer Boolean |
|
members of Class2 xsize of GraphArea ioerror |
Note that built-in functions do not return floating point values.
In every ESL statement in which a value is required, a particular type is associated with that value. For example, when you specify coordinate positions in the definition of an object, integer values are needed:
disabled key Message at position 50 100
key HelpKey at position Xpos Ypos
In the second example, Xpos and Ypos are constants or variables that contain integer values.
When you specify data to be sent to an application program, a string value is needed:
send "Logoff\n" to Newswire
When you specify a loop, a boolean value is needed:
while (true) loop
or
while (A > B) loop
# If A is greater than B, the loop will be executed.
