Operator New
Operator to dynamically allocate memory and construct data of a specified type
Declare Operator New ( size As UInteger ) As Any Ptr
Declare Operator new[] ( size As UInteger ) As Any Ptr
result = New datatype
size
The New operator dynamically allocates memory and constructs a specified data type. For simple types, like integers, an initial value can be given. For types without constructors, initial values can be specified for each field. Types that have constructors can have their constructors called by New as well. If no initializers are given, the default values for those types will be set.
New[] is the array-version of the New operator and allocates enough memory for the specified number of objects. The default constructor for the type will be used to set the initial values for each item.
Objects created with New must be freed with Delete. Memory allocated with New[] must be freed with Delete[], the array-version of Delete. You cannot mix and match the different versions of the operators.
Specifying an initial value of Any, as in new datatype(any) will allocate memory for the type, but not initialize the data. This is only valid on data types that do not have constructors.
Specifying an initial value of Any, as in new datatype[count]{any} will allocate memory for the array, but not initialize the data. This is only valid on data types that do not have constructors.
Syntax
Declare Operator New ( size As UInteger ) As Any Ptr
Declare Operator new[] ( size As UInteger ) As Any Ptr
Usage
result = New datatype
or
result = New datatype ( initializers, ... )or
result = New datatype[ count ]Parameters
size
Number of bytes to allocate.
initializersInitial value(s) for the variable.
datatypeName of the data type to create.
countExact number of elements to allocate.
Return Value
Description
The New operator dynamically allocates memory and constructs a specified data type. For simple types, like integers, an initial value can be given. For types without constructors, initial values can be specified for each field. Types that have constructors can have their constructors called by New as well. If no initializers are given, the default values for those types will be set.
New[] is the array-version of the New operator and allocates enough memory for the specified number of objects. The default constructor for the type will be used to set the initial values for each item.
Objects created with New must be freed with Delete. Memory allocated with New[] must be freed with Delete[], the array-version of Delete. You cannot mix and match the different versions of the operators.
Specifying an initial value of Any, as in new datatype(any) will allocate memory for the type, but not initialize the data. This is only valid on data types that do not have constructors.
Specifying an initial value of Any, as in new datatype[count]{any} will allocate memory for the array, but not initialize the data. This is only valid on data types that do not have constructors.
Example
Type Rational
As Integer numerator, denominator
End Type
Scope
' Create and initialize a Rational, and store it's address.
Dim p As Rational Ptr = New Rational(3, 4)
Print p->numerator & "/" & p->denominator
' Destroy the rational and give its memory back to the system.
Delete p
End Scope
Scope
' Allocate memory for 100 integers, store the address of the first one.
Dim p As Integer Ptr = New Integer[100]
' Assign some values to the integers in the array.
For i As Integer = 0 To 99
p[i] = i
Next
' Free the entire integer array.
Delete[] p
End Scope
As Integer numerator, denominator
End Type
Scope
' Create and initialize a Rational, and store it's address.
Dim p As Rational Ptr = New Rational(3, 4)
Print p->numerator & "/" & p->denominator
' Destroy the rational and give its memory back to the system.
Delete p
End Scope
Scope
' Allocate memory for 100 integers, store the address of the first one.
Dim p As Integer Ptr = New Integer[100]
' Assign some values to the integers in the array.
For i As Integer = 0 To 99
p[i] = i
Next
' Free the entire integer array.
Delete[] p
End Scope
Dialect Differences
- Only available in the -lang fb dialect.
Differences from QB
- New to FreeBASIC
See also
