本章小结
本章主要论述了数组、指针和引用。在C + +语言中，它们是相互交织在一起的，对其中一个概念的理解有助于对其他槪念的理解。
数组是一个由若干相同类型数据组成的集合，数组中特定的元素通过下标来访问。数组可以具有一维到多维的多种类型，一维数组是最常见的，字符数组是最常使用的，它可以用来保存字符串。标准c++语言没有定义内置的字符串数据类型，而是将字符串作为字符数组来实现。 数组为创建相关变量的列表提供了一种便利的方法。数组由连续存储单元组成，它的起始地址对应于数组的第一个元素，数组名本身是数组的首地址，它使得数组作为函数参数来传递从空间 利用上显得更合理。
在C++中，数组和指针有着密切的关系。指针是一个包含内存地址的对象，它不仅仅是地址，还与所指对象类型相关。通常，指针被用来访问另一个对象的值，这个另外的对象常常是一个数组，当程序把一个数组传递给函数时，C++实际上把数组第一个元素的地址传递给该函数3 通过递增指针的值，可以使指针直接指向数组的下一个元素。
引用是C++独有的特性，引用实质上就是另一个变量的别名。
使用new和delete运算符可以进行动态存储分配。这样，程序就能在运行时指定所申请内存空间的大小。
程序清单
4.1 arrayone.cpp 使用数组
// arrayone.cpp -- small arrays of integers
#include "stdafx.h"
#include <iostream>
int main()
{
using namespace std;
int yams[3]; //creates array with three elements
yams[0] = 7; //assign value to first element
yams[1] = 8;
yams[2] = 6;
int yamcosts[3] = {20,30,5};//create, initialize array
//NOTE:if your C++ compiler or translator can't initialize this array,use static int yamcosts[3] instead of int yamcosts[3]
cout << "Total yams = ";
cout << yams[0] + yams[1] + yams[2] << endl;
cout << "The package with " << yams[1] << " yams costs ";
cout << yamcosts[1] << " cents per yam.\n";
int total = yams[0] * yamcosts[0] + yams[1] * yamcosts[1];
total = total + yams[2] * yamcosts[2];
cout << "The total yam expense is " << total << " cents.\n";
cout << "\nSize of yams array = " << sizeof yams;
cout << " bytes.\n";
cout << "Size of one element = " << sizeof yams[0];
cout << " bytes.\n";
return 0;
}
4.2 string.cpp 使用cstring
//string.cpp -- storing strings in an array
#include "stdafx.h"
#include <iostream>
#include <cstring>
int main()
{
using namespace std;
const int Size = 15;
char name1[Size]; //empty array
char name2[Size] = "C++owboy";//initialized array
//NOTE:some implementations may require the static keyword to initialize the array name2
cout << "Howdy! I'm " << name2 << "! What's your name?\n";
cin >> name1;
cout << "well, " << name1 << ", your name has ";
cout << strlen(name1) << " letters and is stored\n";
cout << "in an array of " << sizeof(name1) << " bytes \n";
cout << "Your initial is " << name1[0] << ".\n";
name2[3] = '\0'; //set to null character
cout << "Here are the firsr 3 charaters of my name: ";
cout << name2 << endl;
return 0;
}
4.3 instr1.cpp 字符串输入
//instr1.cpp -- reading more than one string
#include "stdafx.h"
#include <iostream>
int main()
{
using namespace std;
const int ArSize = 20;
char name[ArSize];
char dessert[ArSize];
cout << "Enter your name:\n";
cin >> name;
cout << "Enter your favorite dessert:\n";
cin >> dessert;
cout << "I have some delicious " << dessert << " for you. " << name << ".\n";
return 0;
}
//输入时如果有空格，就相当于输入了两个数组，因为cin在识别输入时，是将字符串放到数组中，并自动在结尾添加空字符
4.4 instr2.cpp 使用cin.getline
//instr2.cpp -- reading more than one word with getline
#include "stdafx.h"
#include <iostream>
int main()
{
using namespace std;
const int ArSize = 20;
char name[ArSize];
char dessert[ArSize];
cout << "Enter your name:\n";
cin.getline(name, ArSize);//reads through newline
cout << "Enter your favorite dessert:\n";
cin.getline(dessert, ArSize);
cout << "I have some delicious " << dessert;
cout << " for you. " << name << " .\n";
return 0;
}
//getline()函数每次读取一行
4.5 instr3.cpp 拼接方式
//instr3.cpp -- reading more than one word with get() & get()
#include "stdafx.h"
#include <iostream>
int main()
{
using namespace std;
const int ArSize = 20;
char name[ArSize];
char dessert[ArSize];
cout << "Enter your name:\n";
cin.get(name, ArSize).get();//reads string,newline
cout << "Enter your favorite dessert:\n";
cin.get(dessert, ArSize).get();
cout << "I have some delicious " << dessert;
cout << " for you. " << name << " .\n";
return 0;
}
4.6 numstr.cpp 混合字符串和数字
//numstr.cpp -- following number input with line input
#include "stdafx.h"
#include <iostream>
int main()
{
using namespace std;
cout << "What year was your house built?\n";
int year;
cin >> year;
cout << "What is its street address?\n";
char address[80];
cin.getline(address, 80);
cout << "Year built: " << year << endl;
cout << "Address: " << address << endl;
cout << "Done!\n";
return 0;
}
4.7 strtype1.cpp string类
//strtype1.cpp -- using the C++ string class
#include "stdafx.h"
#include <iostream>
#include <string> //make string class available
int main()
{
using namespace std;
char charr1[20]; //create an empty array
char charr2[20] = "jaguar";//create an initialized array
string str1; //create an empty string object 可以声明为简单变量而不是数组
string str2 = "panther"; //create an initialized string
cout << "Enter a kind of feline: ";
cin >> charr1;
cout << "Enter another kind of feline: ";
cin >> str1; //use cin for input
cout << "Here are some felines:\n";
cout << charr1 << " " << charr2 << "" << str1 << " "
<< str2 << endl; //use cout for output
cout << "The third letter in " << charr2 << " is "
<< charr2[2] << endl;
cout << "The third letter in " << str2 << " is "
<< str2[2] << endl; //use array notation
return 0;
}
4.8 strtype2.cpp string类
//strtype2.cpp -- assigning,adding,and appending
#include "stdafx.h"
#include <iostream>
#include <string> //make string class available
int main()
{
using namespace std;
string s1 = "penguin";
string s2, s3;
cout << "You can assign one string object to another: s2 = s1\n";
s2 = s1;
cout << "s1: " << s1 << ", s2:" << s2 << endl;
cout << "You can assign a C-style string to a string object.\n";
cout << "s2 = \"buzzard\"\n";
s2 = "buzzard";
cout << "s2: " << s2 << endl;
cout << "You can concatenate strings: s3 = s1 + s2\n";
s3 = s1 + s2;
cout << "s3: " << s3 << endl;
cout << "You can append strings.\n";
s1 += s2;
cout << "s1 += s2 yields s1 = " << s1 << endl;
s2 += " for a day";
cout << "s2 += \"for a day\" yields s2 = " << s2 << endl;
return 0;
}
4.9 strtype3.cpp string类
//strtype3.cpp -- more string class features
#include "stdafx.h"
#include <iostream>
#include <string> //make string class available
#include <cstring> //C-style string library
int main()
{
using namespace std;
char charr1[20]; //create an empty array
char charr2[20] = "jaguar";//create an initialized array
string str1; //create an empty string object 可以声明为简单变量而不是数组
string str2 = "panther"; //create an initialized string
//assignment for string objects and character arrays
str1 = str2; //copy str2 to str1
strcpy(charr1, charr2); //copy charr2 to charr1
//appending for string objects and character arrays
str1 += " paste"; //add paste to end of strl
strcat(charr1, " juice"); //add juice to end of charr1
//finding the length of a string object and aC-style string
int len1 = str1.size(); //obtain length of str1
int len2 = strlen(charr1); //obtain length of charr1
cout << "The string " << str1 << " contains "
<< len1 << " characters.\n";
cout << "The string " << charr1 << " contains "
<< len2 << " characters.\n";
return 0;
}
//strcpy和strcat函数可能会报错：error C4996: : This function or variable may be unsafe. Consider using fopen_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.
//解决方法：https://jingyan.baidu.com/article/ce436649fd61543773afd32e.html
4.10 strtype4.cpp string类
//strtype4.cpp -- line input
#include "stdafx.h"
#include <iostream>
#include <string> //make string class available
#include <cstring> //C-style string library
int main()
{
using namespace std;
char charr[20];
string str;
cout << "Length of string in charr before input: "
<< strlen(charr) << endl;//对于未被初始化的数据，第一个空字符的出现位置是随机的，因此得到的结果可能不同
cout << "Length of string in str before input: "
<< str.size() << endl;
cout << "Enter a line of text:\n";
cin.getline(charr, 20); //indicate maximum length
cout << "You entered: " << charr << endl;
cout << "Enter another line of text:\n";
getline(cin, str);//cin now an argument ; no length specifier
cout << "You entered: " << str << endl;
cout << "Length of string in charr after input: "
<< strlen(charr) << endl;
cout << "Length of string in str after input: "
<< str.size() << endl;
return 0;
}
4.11 structur.cpp 初始化结构
//structur.cpp -- a simple structure
#include "stdafx.h"
#include <iostream>
struct inflatable//structure declaration
{
char name[20];
float volume;
double price;
};
int main()
{
using namespace std;
inflatable guest =
{
"Glorious Gloria",//name value
1.88,// volume value
29.99//price value
};//guest is a structure variable of type inflatable
//It's initialized to the indicated values
inflatable pal =
{
"Audacious Arthur",
3.12,
32.99
};//pal is a second variable of type inflatable
//NOTE:some implementations require using
//static inflatable guest =
cout << "Expand your guest list with " << guest.name;
cout << " and " << pal.name << "!\n";//pal.name is the name member of the pal variable
cout << "You can have both for $";
cout << guest.price + pal.price << "!\n";
return 0;
}
4.12 assgn_st.cpp 结构赋值
//assgn_st.cpp--assigning structures
#include "stdafx.h"
#include <iostream>
struct inflatable
{
char name[20];
float volume;
double price;
};
int main()
{
using namespace std;
inflatable bouquet =
{
"sunflowers",
0.20,
12.49
};//注意加分号
inflatable choice;
cout << "bouquet: " << bouquet.name << " for $";
cout << bouquet.price << endl;
choice = bouquet;
cout << "choice: " << choice.name << " for $";
cout << choice.price << endl;
return 0;
};
4.13 arrstruc.cpp 结构数组
//arrstruc.cpp -- an array of structures
#include "stdafx.h"
#include <iostream>
struct inflatable
{
char name[20];
float volume;
double price;
};
int main()
{
using namespace std;
inflatable guests[2]=
{
{"Bambi",0.5,21.99},
{"Godzilla",2000,565.99}
};
cout << "The guests " << guests[0].name << " and " << guests[1].name
<< "\nhave a combined volume of "
<< guests[0].volume + guests[1].volume << " cubic feet.\n";
return 0;
}
4.14 address.cpp &运算符的用法
//address.cpp -- using the & operator to find address
#include "stdafx.h"
#include <iostream>
int main()
{
using namespace std;
int donuts = 6;
double cups = 4.5;
cout << "donuts value = " << donuts;
cout << " and donuts address = " << &donuts << endl;
//NOTE:you may need to use unsigned (&donuts) and unsigned (&cups)
cout << "cups value = " << cups;
cout << " and cups address = " << &cups << endl;
return 0;
}
4.15 pointer.cpp 声明指针
//pointer.cpp -- our first pointer variable
#include "stdafx.h"
#include <iostream>
int main()
{
using namespace std;
int updates = 6;//declare a variable
int * p_updates;//declare pointer to an int
p_updates = &updates;//assign address of int to pointer
//express values two ways
cout << "Values: updates = " << updates;
cout << " , p_updates = " << *p_updates << endl;
//express address two ways
cout << "Addresses: &updates = " << &updates;
cout << ", p_updates = " << p_updates << endl;
//use pointer to change value
*p_updates = *p_updates + 1;
cout << "Now updates = " << updates << endl;
return 0;
}
4.16 init_ptr.cpp 将指针初始化为一个地址
//init_ptr.cpp -- initialize a pointer
#include "stdafx.h"
#include <iostream>
int main()
{
using namespace std;
int higgens = 5;
int * pt = &higgens;
cout << "Value of higgens = " << higgens
<< "; Address of higgens = " << &higgens << endl;
cout << "Value of *pt = " << *pt
<< "; Value of pt = " << pt << endl;
return 0;
}
4.17 use_new.cpp new用于两种不同类型
//use_new.cpp -- using the new operator
#include "stdafx.h"
#include <iostream>
int main()
{
using namespace std;
int nights = 1001;
int * pt = new int;
*pt = 1001;
cout << "night value = ";
cout << nights << ": location " << &nights << endl;
cout << "int ";
cout << "value = " << *pt << ": location = " << pt << endl;
double * pd = new double;
*pd = 10000001.0;
cout << "double ";
cout << "value = " << *pd << ": location = " << pd << endl;
cout << "location of pointer pd: " << &pd << endl;
cout << "size of pt = " << sizeof(pt);
cout << "size of *pt = " << sizeof(*pt) << endl;
cout << "size of pd = " << sizeof(pd);
cout << "size of *pd = " << sizeof(*pd) << endl;
return 0;
}
4.18 arraynew.cpp 用new创建动态数组
//arraynew.cpp -- using the new operator for arrays
#include "stdafx.h"
#include <iostream>
int main()
{
using namespace std;
double *p3 = new double[3];
p3[0] = 0.2;
p3[1] = 0.5;
p3[2] = 0.8;
cout << "p3[1] is " << p3[1] << ".\n";
p3 = p3 + 1;
cout << "Now p3[0] is " << p3[0] << " and ";
cout << "p3[1] is " << p3[1] << ".\n";
p3 = p3 - 1;
delete[] p3;
return 0;
}
4.19 addpntrs.cpp 指针算数
//addpntrs.cppp -- pointer addition
#include "stdafx.h"
#include <iostream>
int main()
{
using namespace std;
double wages[3] = { 10000.0, 20000.0, 30000.0 };
short stacks[3] = { 3,2,1 };
//Here are two ways to get the address of an array
double * pw = wages; //name of an array = address
short * ps = &stacks[0];//or use address operator
//with array element
cout << "pw = " << pw << ", *pw = " << *pw << endl;
pw = pw + 1;
cout << "add 1 to the pw pointer : \n";
cout << "pw = " << pw << ", *pw = " << *pw << "\n\n";
cout << "ps = " << ps << ", *ps = " << *ps << endl;
ps = ps + 1;
cout << "add 1 to the ps pointer:\n";
cout << "ps = " << ps << ", *ps = " << *ps << "\n\n";
cout << "access two element with array notation\n";
cout << "stacks[0] = " << stacks[0]
<< "stack[1] = " << stacks[1] << endl;
cout << "access two element with pointer notation\n";
cout << "*stacks = " << *stacks
<< ", *{stacks + 1} = " << *(stacks + 1) << endl;
cout << sizeof(wages) << " = size of wages array\n";
cout << sizeof(pw) << " size of pw pointer\n";
return 0;
}
4.20 ptrstr.cpp 使用不同形式的字符串
//ptrstr.cpp -- using pointers to strings
#include "stdafx.h"
#include <iostream>
#include <cstring> //declare strlen(),strcpy()
int main()
{
using namespace std;
char animal[20] = "bear"; //animal holds bear
const char * bird = "wren"; //bird holds address of string
char * ps; //uninitialized
cout << animal << " and "; //display bear
cout << bird << "\n"; //display wren
// cout << ps << "\n";//may display garbage, may cause a crash
cout << "Enter a kind of animal: ";
cin >> animal; //ok if input < chars
// cin >> ps ;Too horrible a blunder to try; ps doesn't point to allocated space
ps = animal; //set ps to point to string
cout << ps << "!\n"; //ok, same as using animal
cout << "Before using strcpy():\n";
cout << animal << " at " << (int *)animal << endl;
cout << ps << " at " << (int *)ps << endl;
ps = new char[strlen(animal) + 1];//get new storage
strcpy(ps, animal); //copy string to new storage
cout << "After using strcpy():\n";
cout << animal << " at " << (int *)animal << endl;
cout << ps << " at " << (int *)ps << endl;
delete[] ps;
return 0;
}
4.21 newstrct.cpp 访问指针成员
//newstrct.cpp -- using new with a structure
#include "stdafx.h"
#include <iostream>
struct inflatable // structure definition
{
char name[20];
float volume;
double price;
};
int main()
{
using namespace std;
inflatable * ps = new inflatable; // allot memory for structure
cout << "Enter name of inflatable item: ";
cin.get(ps->name, 20); // method 1 for member access
cout << "Enter volume in cubic feet: ";
cin >> (*ps).volume;//method 2 for member access
cout << "Enter price : $";
cin >> ps->price;
cout << "Name: " << (*ps).name << endl; //method 2
cout << "Volume: " << ps->volume << " cubic feet\n";//method 1
cout << "Price: $" << ps->price << endl; //method 1
delete ps; //free memory used by structure
return 0;
}
4.22 delete.cpp 演示delete
//delete.cpp -- using the delete operator
#include "stdafx.h"
#include <iostream>
#include <cstring>//or string.h
using namespace std;
char * getname(void);//function prototype
int main()
{
char *name;//create pointer but no storage
name = getname();//assign address of string to name
cout << name << " at " << (int *)name << "\n";
delete[] name; // memory freed
name = getname(); //reuse freed mamory
cout << name << " at " << (int *)name << "\n";
delete[] name; // memory freed again
return 0;
}
char * getname() // return pointer to new string
{
char temp[80]; //temporay storage
cout << "Enter last name: ";
cin >> temp;
char * pn = new char[strlen(temp) + 1];
strcpy(pn, temp); //copy string into smaller space
return pn; //temp lost when function ends
}
4.23 mixtypes.cpp 类型组合
//mixtype.cpp -- some type combinations
#include "stdafx.h"
#include <iostream>
struct antarctica_years_end
{
int year;
/*some relly interesting data,etc.*/
};
int main()
{
antarctica_years_end s01, s02, s03;
s01.year = 1998;
antarctica_years_end *pa = &s02;
pa->year = 1999;
antarctica_years_end trio[3];//array of structures
trio[0].year = 2003;
std :: cout << trio->year << std::endl;
const antarctica_years_end * arp[3] = { &s01,&s02,&s03 };
std::cout << arp[1]->year << std::endl;
const antarctica_years_end **ppa = arp;
auto ppb = arp;//C++11 automatic type deduction or else use const antarctica_years_end **ppb = arp;
std::cout << (*ppa)->year << std::endl;
std::cout << (*(ppb + 1))->year << std::endl;
return 0;
}
4.24 choices.cpp vector对象
//choices.cpp -- array variations
#include "stdafx.h"
#include <iostream>
#include <vector> //STL C++98
#include <array>//C+11
int main()
{
using namespace std;
//C,original C++
double a1[4] = { 1.2,2.4,3.6,4.8 };
//C++98 STL
vector<double> a2(4);//create vector with 4 element
//no simple way to initialize in C98
a2[0] = 1.0 / 3.0;
a2[1] = 1.0 / 5.0;
a2[2] = 1.0 / 7.0;
a2[3] = 1.0 / 9.0;
//C++ -- create and initialize array object
array<double, 4> a3 = { 3.14,2.72,1.62,1.41 };
array<double, 4> a4;
a4 = a3;//valid for array object of same size
//use array notation
cout << "a1[2]: " << a1[2] << " at " << &a1[2] << endl;
cout << "a2[2]: " << a2[2] << " at " << &a2[2] << endl;
cout << "a3[2]: " << a3[2] << " at " << &a3[2] << endl;
cout << "a4[2]: " << a4[2] << " at " << &a4[2] << endl;
//misdeed
a1[-2] = 20.2;
cout << "a1[-2]: " << a1[-2] << " at " << &a1[-2] << endl;
cout << "a3[2]: " << a3[2] << " at " << &a3[2] << endl;
cout << "a4[2]: " << a4[2] << " at " << &a4[2] << endl;
return 0;
}
课后编程习题答案
//problem.cpp -- homework
#include "stdafx.h"
#include <iostream>
#include <cstring>
#include <string>
using namespace std;
//problem_1
/*
struct student
{
char fn[20];
char ln[20];
char grade;
int age;
};
void display(student);
int main()
{
cout << "what is your first name?" << endl;
student bs;
cin.getline(bs.fn, asize);
cout << "what is your last name?" << endl;
cin.getline(bs.ln, asize);
cout << "what letter grade do you deserve?" << endl;
cin >> bs.grade;
cout << "what is your age?" << endl;
cin >> bs.age;
display(bs);
return 0;
}
void display(student name)
{
cout << "Name: " << name.fn << "," << name.ln << endl;
cout << "Grade: " << char(name.grade + 1) << endl;
cout << "Age: " << name.age << endl;
}
*/
//problem2
/*
int main()
{
string name, dessert;
cout << "Enter your name: \n";
getline(cin, name);
cout << "Enter your favorite dessert: \n";
getline(cin, dessert);
cout << "I have some delicious " << dessert;
cout << " for you, " << name << ".\n";
return 0;
}
*/
//problem3
/*
int main()
{ char fname[20];
char lname[20];
char fullname[2 * 20 + 1];
cout << "Enter your first name:";//输入名字，存储在fname[]数组中
cin.getline(fname, 20);
cout << "Enter your last name:";//输入姓，存储在lname[]数组中
cin.getline(lname, 20);
strncpy(fullname, lname, 20);//把姓lname 复制到fullname 空数组中
strcat(fullname, ", ");//把“， ”附加到上述fullname 尾部
strncat(fullname, fname, 20);//把fname 名字附加到上述fullname 尾部
fullname[2 * 20] = '\0';//为防止字符型数组溢出，在数组结尾添加结束符
cout << "Here's the information in a single string:" << fullname << endl;//显示组合结果
return 0;
}
*/
//problem4
/*
int main()
{
string fname, lname, attach, fullname;
cout << "Enter your first name:";
getline(cin, fname);//note:将一行输入读取到string 类对象中使用的是getline(cin,str),它没有使用句点表示法，所以不是类方法
cout << "Enter your last name:";
getline(cin, lname);
attach = ", ";
fullname = lname + attach + fname;
cout << "Here's the information in a single string:" << fullname << endl;
return 0;
}
*/
//problem5
/*
struct CandyBar
{
char brand[20];
double weight;
int calory;
};
int main()
{
CandyBar snack = { "Mocha Munch",2.3,350 };
cout << "Here's the information of snack:\n";
cout << "brand:" << snack.brand << endl;
cout << "weight:" << snack.weight << endl;
cout << "calory:" << snack.calory << endl;
return 0;
}
*/
//problem6
/*
struct CandyBar
{
char brand[20];
double weight;
int calory;
};
int main()
{
using namespace std;
CandyBar snack[3] = {
{ "Mocha Munch",2.3,350 },
{ "XuFuJi",1.1,300 },
{ "Alps",0.4,100 }
};
for (int i = 0; i < 3; i++)//利用for 循环来显示snack 变量的内容
{
cout << snack[i].brand << endl
<< snack[i].weight << endl
<< snack[i].calory << endl << endl;
}
return 0;
}
*/
//problem7
/*
struct pizza
{
char company[20];
double diameter;
double weight;
};
int main()
{
using namespace std;
pizza pie;//创建一个名为pie 的结构变量
cout << "What's the name of pizza company:";
cin.getline(pie.company, 20);
cout << "What's the diameter of pizza:";
cin >> pie.diameter;
cout << "What's the weight of pizza:";
cin >> pie.weight;
cout << "company:" << pie.company << endl;
cout << "diameter:" << pie.diameter << " cm" << endl;
cout << "weight:" << pie.weight << " g" << endl;
return 0;
}*/
//problem8
/*
struct pizza//声明结构
{
char company[20];
double diameter;
double weight;
};
int main()
{
using namespace std;
pizza *pie = new pizza;//使用new 创建动态结构
cout << "What's the diameter of pizza:";
cin >> pie->diameter;
cin.get();//读取下一个字符
cout << "What's the name of pizza company:";
cin.get(pie->company, 20);
cout << "What's the weight of pizza:";
cin >> pie->weight;
cout << "company:" << pie->company << endl;
cout << "diameter:" << pie->diameter << " cm" << endl;
cout << "weight:" << pie->weight << " g" << endl;
delete pie;//delete 释放内存
return 0;
}*/
//problem9
/*
struct CandyBar
{
string brand;
double weight;
int calory;
};
int main()
{
CandyBar *snack = new CandyBar[3];
snack[0].brand = "A";//单个初始化由new 动态分配的内存
snack[0].weight = 1.1;
snack[0].calory = 200;
snack[1].brand = "B";
snack[1].weight = 2.2;
snack[1].calory = 400;
snack[2].brand = "C";
snack[2].weight = 4.4;
snack[2].calory = 500;
for (int i = 0; i < 3; i++)
{
cout << " brand: " << snack[i].brand << endl;
cout << " weight: " << snack[i].weight << endl;
cout << " calorie: " << snack[i].calory << endl << endl;
}
delete[] snack;
return 0;
}
*/
//problem10
/*
int main()
{
const int Size = 3;
int success[Size];
cout << "Enter your success of the three times 40 meters running:\n";
cin >> success[0] >> success[1] >> success[2];
cout << "success1:" << success[0] << endl;
cout << "success2:" << success[1] << endl;
cout << "success3:" << success[2] << endl;
double average = (success[0] + success[1] + success[2]) / 3;
cout << "average:" << average << endl;
return 0;
}
*/