HP Prime Graphing NW280AAABA manual Export Radius Export Getradius Begin Inputradius END

variables is given in chapter 22, “Variables”, beginning on page 423.)

In a program you can declare variables for use only within a particular function. This is done using a LOCAL declaration. The use of local variables enables you to declare and use variables that will not affect the rest of the calculator. Local variables are not bound to a particular type; that is, you can store floating-point numbers, integers, lists, matrices, and symbolic expressions in a variable with any local name. Although the system will allow you to store different types in the same local variable, this is poor programming practice and should be avoided.

Variables declared in a program should have descriptive names. For example, a variable used to store the radius of a circle is better named RADIUS than VGFTRFG. You are more likely to remember what the variable is used for if its name matches its purpose.

If a variable is needed after the program executes, it can be exported from the program using the EXPORT command. To do this, the first command in the program (that is, on a line above the program name) would be EXPORT RADIUS. Then, if a value is assigned to RADIUS, the name appears on the variables menu (a) and is visible globally. This feature allows for extensive and powerful interactivity among different environments in the HP Prime. Note that if another program exports a variable with the same name, the most recently exported version will be active.

The program below prompts the user for the value of RADIUS, and exports the variable for use outside the program.

EXPORT RADIUS;

EXPORT GETRADIUS()

BEGIN

INPUT(RADIUS);

END;

512 Programming in HP PPL