第七章━━动态内存分配.ppt
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C++程序设计;主要内容;C++的四个内存区域;动态存储分配;堆内存;new 与 delete 运算符;new 与 delete 运算符;【例】（动态创建变量）
#includeiostream.h
void main ( )
{ int * p = new int ( 100 ) ;
cout *p endl ;
*p = 200 ;
cout *p endl ;
delete p ;
}
【例】（动态创建一维数组）
#includeiostream.h
void main ( )
{ int * p = new int [ 6 ] ;
cout “请输入六个整数：\n” ;
for ( int i=0 ; i6 ; i++ )
cin p[ i ] ;
for ( i=0 ; i6 ; i++ )
cout *( p + i ) ‘\t’ ;
cout endl ;
delete [ ] p ;
};new 与 delete 运算符;【例】（动态创建二维数组）
#includeiostream.h
void main ( )
{ float ( *p1 ) [ 3 ] = new float [ 2 ] [ 3 ] ;
int i , j ;
cout “请输入六个整数：” ;
for ( i=0 ; i2 ; i++ )
for ( j=0 ; j3 ; j++ ) cin p1 [ i ] [ j ] ;
for ( i=0 ; i2 ; i++ )
{ for ( j=0 ; j3 ; j++ )
cout * ( * ( p1+i ) + j ) ‘\t’ ;
cout endl ; }
float *p2 = ( float * ) new float [ 2 ] [ 3 ] ;
cout “请输入六个整数：” ;
for ( i=0 ; i6 ; i++ ) cin p2 [ i ] ;
for ( i=0 ; i6 ; i++ )
{ cout * ( p2+i ) ‘\t’ ;
if ( ( i+1 ) %3 ==0 ) cout endl ; }
delete [ ] p1 ;
delete [ ] p2 ; };动态存储分配的几点说明;动态存储分配的几点说明;使用 new 和 delete 的几点说明;动态创建对象;【例】（ 学生类、new创建动态对象， delete释放动态对象）
# includeiostream.h
# includestring.h
class Student
{ int id ;
char name[ 8 ] ;
int score ;
public:
Student ( int i=0, char *na=0, int s=0 )
{ id = i ; strcpy( name, na ) ; score = s ;
cout “对象地址=” (int) this “\t构造(” name “)了!\n” ; }
~Student ( )
{ cout “对象地址=” (int) this “\t析构(” name “)了!\n” ; }
void print( )
{ cout “学号=” id “ \t姓名=” name “\t成绩=” score ‘\n’ ; }
};
Student *p1 = new Student ( 111, “张军”, 99 ) ;
void main( )
{ p1-print( ) ; delete p1 ;
Student *p2 = new Student ( 222 , “王红” , 88 ) ;
p2-print( ); //注意：此处漏写 delete p2;
} ;【例】（ 点类、new创建动态对象数组，delete释放动态对象数组）
# includeio
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