# Directives

PRECISION | Change Current Precision

## Format

PRECISION num [ FOR OBJECT ]
Where:

num | Precision to which to round. Numeric expression. Integer range 0 to 18 or use -1 to switch to scientific notation.
FOR OBJECT | Object Oriented Programming (OOP) - Optional keywords for setting the default PRECISION for all subsequent method invocations within the current object instance, except for those that have CLASS definitions that specifically declare a PRECISION to use (preserving encapsulation).

## Description

Use the PRECISION directive to change the number of digits PxPlus maintains to the right of the decimal point. (Internally, PxPlus makes all calculations using 18 digits of accuracy; however, when numeric data is output, the value is rounded and returned using the number of digits set in the PRECISION directive.)

The precision setting is also used in conjunction with the ROUND directive. If rounding is enabled (default mode), values assigned to variables through the LET directive will be rounded to the PRECISION num specified.

#### Note:
Precision is automatically reset to the value found in the 'PD' system parameter by the following directives: BEGIN, CLEAR, END, LOAD, RESET, STOP, RUN. It will be set to 2 by default by a START directive.

The FLOATINGPOINT directive overrides the PRECISION directive. PRECISION -1 can also be used to have PxPlus switch to FLOATINGPOINT (scientific notation). Use another numeric value in the PRECISION directive (e.g. PRECISION 2) to cancel scientific notation.

In Object Oriented Programming (OOP), PRECISION is used to force a predefined precision setting for objects. This sets the precision before each function and restores precision upon exit from a function.

## See Also

ROUND Control Rounding
FLOATINGPOINT Switch to Scientific Notation

## Example

for A=0 to 6
precision A
print 1/3,
next A
print "DONE";
stop
->run
0 0.3 0.33 0.333 0.3333 0.33333 0.333333 DONE
precision 7
print 1/3,@(15),"PRECISION: ",tcb(14)
begin ! Resets precision to 2
print 1/3,@(15),"PRECISION: ",prc
end
->run
0.3333333 PRECISION: 7
0.33 PRECISION: 2