STRING: Defining VISTA String Variables



STRING defines string variables. String variables are names to which a character string is associated.

STRING works like PRINTF (see that section of the help information), except that the name of the string variable being defined appears between the command STRING and the format string. As in PRINTF, you can define strings directly, as in:

Remember that multiple words to be considered as one string must be enclosed in quotes. If you wish to define a blank string, you must define it as a single blank in quotes, as in:

You may also define strings using expression evaluation as in:

which evaluates the numeric variable J, then substitutes its value into the string beginning FILE..., and loads the final string into the stack of string variables under the name J. In this example, the value of the string variable NAME is FILE007.

If the first character of the format string is a question mark, STRING will print the remainder of the format string as a prompt, then pause while you enter the string. This allows the interactive definition of strings. If the format string contains only a question mark, then the prompt will be 'Enter' followed by the name of the string variable which is being defined. Examples:

You CANNOT evaluate arithmetic expressions when defining strings interactively. Thus
\begin{hanging}
\item{STRING FILE '?Enter a file for image \%I2 ' J}
\end{hanging}
will NOT work. The newline character (\n) will also not work.

You can list all defined strings with the command PRINT STRINGS.

A string variable can be substituted into a command line by enclosing the name of the string in braces. See HELP SUBSTITUTE for more information, plus information about printing STRINGS.

String variables are stored in a different stack from numeric variables. Thus it is possible to have a string variable and a numeric variable with the same name.