生存期对象随新
随 新 运算符销毁对象时,它们时定义的范围退出。由于 新 运算符返回其分配的指针对象,程序必须定义与适当范围的指针访问这些对象。例如:
// expre_Lifetime_of_Objects_Allocated_with_new.cpp
// C2541 expected
int main()
{
// Use new operator to allocate an array of 20 characters.
char *AnArray = new char[20];
for( int i = 0; i < 20; ++i )
{
// On the first iteration of the loop, allocate
// another array of 20 characters.
if( i == 0 )
{
char *AnotherArray = new char[20];
}
}
delete [] AnotherArray; // Error: pointer out of scope.
delete [] AnArray; // OK: pointer still in scope.
}
对于指针 AnotherArray 超出该示例中的范围,对象可能不再被删除。