**Parameters** in Pascal are the variables passed to a function or procedure. We use parameters to pass data we want to use in a function or procedure. There are four types of parameters in Pascal:

## Untyped parameters
**Untyped parameters** are parameters that have no type. `Variable`, `constant`, and `out` parameters can also be untyped.

## Syntax

Untyped parameters are passed to a function, as follows:
```pascal
function (_parameterType_ _parameterName_): _returnType_;
begin
   //function body
end
```

Similarly, untyped parameters are passed to a procedure, as follows:
```pascal
procedure (_parameterType_ _parameterName_);
begin
   //procedure body
end
```
* **`_parameterType_`**: The type of the parameter. It can be `var` for *variable parameter*, `const` for *constant parameter*, or `out` for *out parameter*.
* **`_parameterName_`**: The name of the untyped parameter.
* **`_returnType_`**: The data type of the return value of the function.

>Note: 
>* The address of the untyped parameter is passed to the function/procedure. 
>* The function/procedure does not know the data type of the untyped parameter.
>* An untyped parameter must be typecasted to use in an assignment or assign a value to it.

## Code
Consider the code snippet below, which demonstrates the use of the untyped parameters.


program function1;
var
   a, b, calSum : Integer;
   
function sum(const a, b): Integer;
var
a2, b2 : Integer;
begin
   a2 := Integer(a);
   b2 := Integer(b);
   sum := a2 + b2;;//store return value in variable having same name as the name of function
end;

begin
   a := 5;
   b := 10;
   writeln('');
   calSum := sum(a, b);
   writeln(a, ' + ', b, ' = ', calSum);
end.

pascal

## Explanation
A function `sum()` is declared in *line 5* that calculates the sum of two numbers passed to it as parameters. The parameters passed to the `sum()` function are untyped parameters. The untyped parameters `a` and `b` are typecasted to integers in *line 9* and *line 10* respectively. After typecasting, the sum is calculated and returned.

What are untyped parameters in Pascal?

Untyped parameters

Syntax

Code

Explanation