# Parameter ## Content

Class Parameter

java.lang.Object
com.grapecity.documents.excel.Parameter
public class Parameter extends Object
Represents a parameter definition for a custom function.

A Parameter describes the metadata for one function argument, including its name, description, value type, default value, and whether the argument can accept references or custom objects. Use this class when defining parameters for CustomFunction or AsyncCustomFunction instances.


 class DiscountPriceFunction extends CustomFunction {
     DiscountPriceFunction(Parameter[] parameters) {
         super("DISCOUNT_PRICE", FunctionValueType.Number, parameters);
     }

     @Override
     public Object evaluate(Object[] arguments, ICalcContext context) {
         return (double) arguments[0] * (1 - (double) arguments[1]);
     }
 }

 Parameter priceParameter = new Parameter("price", "Original price.", FunctionValueType.Number, 0d);
 Parameter discountParameter = new Parameter("discount", "Discount rate.", FunctionValueType.Number, 0d);
 Workbook.AddCustomFunction(new DiscountPriceFunction(new Parameter[] {
     priceParameter,
     discountParameter
 }), true);
 worksheet.getRange("A1").setFormula("=DISCOUNT_PRICE(100,0.15)");
 Object discountedPrice = worksheet.getRange("A1").getValue();