开始刷《C++Primer》这本书,会在博客上更新课后习题。
水平有限,如有有误之处,希望大家不吝指教!
不断学习中,欢迎交流!
第一二章课后题
练习1.3
#include<iostream>
int main(){
std::cout<<"Hello world"<<std::endl;
return 0;
}
练习1.4
#include<iostream>
int main(){
std::cout << "Input two numbers: " << std::endl;
int a, b;
std::cin >> a >> b;
std::cout << a <<" * "<< b << " = " << a * b << std::endl;
}
练习1.5
#include<iostream>
int main(){
std::cout << "Input two numbers: " << std::endl;
int a, b;
std::cin >> a >> b;
std::cout << a;
std::cout<<" * ";
std::cout<< b ;
std::cout<< " = " ;
std::cout<< a * b ;
std::cout<< std::endl;
}
练习1.6
不合法,第一行有分号表示语句结束,改为如下:
#include<iostream>
int main(){
std::cout << "Input two numbers: " << std::endl;
int a, b;
std::cin >> a >> b;
std::cout << "The sum of "<< a << " and " << b<< " is " << a + b <<std::endl;
return 0;
}
练习1.7
#include<iostream>
int main(){
/*
/* */注释不能嵌套!
*/
return 0;
}
练习1.8
第三行错误,因前双引号被注释掉了,后双引号不匹配。
#include<iostream>
int main(){
std::cout << "/*"<<std::endl;
std::cout << "*/"<<std::endl;
//std::cout << /* "*/" */<<std::endl;
std::cout << /* "*/" /* "/*" */<<std::endl;
return 0;
}
练习1.9
#include<iostream>
int main(){
int sum = 0, val = 50;
while (val <= 100){
sum += val;
++val;
}
std::cout << sum << std::endl;
return 0;
}
练习1.10
#include<iostream>
int main(){
int sum = 0, val = 10;
while (val >= 0){
sum += val;
--val;
}
std::cout << sum << std::endl;
return 0;
}
练习1.11
#include<iostream>
int main(){
int a, b;
std::cin >> a >> b;
while (a <= b){
std::cout << a << " ";
++a;
}
return 0;
}
练习1.12
程序的功能是求[-100,100]范围内的整数的和,sum的终值为0
练习1.14
已知循环次数的时候用for简便,未知时用while简便。
练习1.16
#include<iostream>
int main(){
int a, sum = 0;
while(std::cin >> a){
sum += a;
}
std::cout << sum;
return 0;
}
练习1.19
#include<iostream>
int main(){
int a, b;
std::cin >> a >> b;
if( a > b ){
int temp = a;
a = b;
b = temp;
}
while (a <= b){
std::cout << a << " ";
++a;
}
return 0;
}
练习1.20
#include <iostream>
#include "Sales_item.h"
int main(){
Sales_item book;
while(std::cin >> book){
std::cout << "Record: " << book <<std::endl;
}
return 0;
}
练习1.21
#include <iostream>
#include "Sales_item.h"
int main(){
Sales_item book1, book2;
std::cin >> book1 >> book2;
std::cout << book1 + book2 <<std::endl;
return 0;
}
练习2.8
#include<iostream>
int main(){
cout<<"2M"<<'\n';
cout<<'2'<<'\t'<<'M'<<'\n';
}
练习2.9
a.需要在cin前定义变量名
b.3.14强制转换为Int有精度损失
c.wage未定义
d.同b
练习2.15
a.定义合法但有精度损失
b.引用类型的初始值必须是一个对象
c.正确
d.同b
练习2.17
10 10
练习2.27
a.不合法,引用r的赋值对象必须是一个对象
b.合法,将p2设置为一个常量指针,初始化为i2对象的地址
c.合法,将i设为常量-1,r设置为常量的引用
d.合法,将p3设为指向常量的常量指针,初始化为i2的地址
e.合法,将p1设为指向常量的指针,初始化为i2的地址
f.不合法,常量指针必须初始化
g.合法
练习2.28
a.不合法,常量指针必须初始化
b.不合法,同a
c.不合法,常量ic未初始化
d.不合法,同a
e.合法。
原文地址:https://www.cnblogs.com/Mered1th/p/10480841.html
时间: 2024-10-13 23:25:25