Operator * (Value Of)operator

Dereferences a pointer

Syntax

Declare Operator * ( ByRef rhs As T Pointer ) ByRef As T

Parameters

Return value

Returns a reference to the value stored at the address rhs.

Description

Operator * (Value of) returns a reference to the value stored at an address, and is often called the dereference operator. The operand is not modified in any way.
Any type of Pointer can be dereferenced except for an Any Pointer.

As a reference, the result of this operator can be used on the left-hand side of assignments.

This operator must not be used in case of null pointer because reference is undefined (inducing runtime error).
Otherwise, the user must ensure that the pointer value induces access to a valid memory. Otherwise, results are undefined.

This operator can be overloaded for user-defined types.

Remarks

Usage

result = * rhs

or

* rhs = value

Dialect Differences

• In the -lang qb dialect, this operator cannot be overloaded.
  
  

Differences from QB

• New to FreeBASIC
  
  

See also

• Operator @ (Address Of)
  
• Operator [] (Pointer Index)
  
• Pointers
  
  

Example

'This program demonstrates the use of * to utilize the value a pointer points to.

Dim a As Integer

Dim pa As Integer Ptr



pa=@a 'Here, we use the @ operator to point our integer ptr at 'a'.

' 'a' is, in this case, a standard integer variable.



a=9     'Here we give 'a' a value of 9.



Print "The value of 'a' is";*pa 'Here, we display the value of 'a' using a pointer. 



*pa = 1 'Here we use our pointer to change the value of 'a'

Print "The new value of 'a' is";a 'Here we display the new value of 'a'.

Output:

The value of 'a' is 9
The new value of 'a' is 1

Reference

• Documented in KeyPgOpValueOf.html