ProvideX V8.20 > Language Reference > Preface

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Numeric Expressions and Variables

When a syntax format in this manual includes a numeric variable like chan, index or

num (lowercase), you can normally substitute a numeric expression consisting of

variables, literals, functions, and operators. For instance, your value could be something

like HFN or 4 or NUM(A1$)*3-2. (NUM in upper case is the function.) When numeric

variables are used in numeric expressions, subscripts are allowed; e.g., COST[4].

Example:

To apply the format FOR var=first TO last[ STEP val] ...

FOR I=1 TO 10 or

FOR LEAPS=-10 TO XYZ STEP ABC*.1

Note: Exceptions and valid values are stated when there are restrictions on the use of

numeric or string expressions in a format (e.g., where only variable names are allowed).

String Expressions and Variables

When a syntax format in this manual includes a string variable like prog_name$ or

title$, you can normally substitute a string expression consisting of variables, literals,

functions, and operators; e.g., PRINT "Printing "+REPORT$. When string

variables are used in string expressions, subscripts and substrings are allowed; e.g.,

CUSTOMER$(15,4).

Example:

For the CHECK_BOX READ [*]ctl_id,state$[,mode$][,ERR=stmtref] format, you

need string variables to receive the current state and optionally, the mode of

selection.

CHECK_BOX READ 14000,ON_OFF$,KEYSTROKE$