Gets and sets the expression (i.e. "22.064 mm") used to calculate the value of the parameter
# Get the value of the property.propertyValue = userParameter_var.expression# Set the value of the property.userParameter_var.expression = propertyValue
#include <Fusion/Fusion/UserParameter.h>// Get the value of the property.string propertyValue = userParameter_var->expression();// Set the value of the property, where value_var is a string.bool returnValue = userParameter_var->expression(value_var);