循环语句中if break，if break else ,if break else break区别
案例代码#include<iostream>
using namespace std;
#include<string>
#define MAX 1000
struct Person
{
string m_Name;
intm_Sex;
int m_Age;
string m_Phone;
string m_Addr;
};
struct Addressbooks
{
struct Person personArray;
int m_Size;
};
void showMenu()
{
cout << "******1.添加联系人******" << endl;
cout << "******2.显示联系人******" << endl;
cout << "******3.删除联系人******" << endl;
cout << "******4.查找联系人******" << endl;
cout << "******5.修改联系人******" << endl;
cout << "******6.清空联系人******" << endl;
cout << "******0.退出通讯录******" << endl;
}
void addPerson(struct Addressbooks* abs)
{
if (abs->m_Size == MAX)
{
cout << "通讯录已满，无法再输入" << endl;
system("pause");
system("cls");
}
else
{
cout << "请输入姓名" << endl;
string name;
cin >> name;
abs->personArray.m_Name = name;
cout << "请输入性别" << endl;
cout << "1----男" << endl;
cout << "2----女" << endl;
int sex = 0;
while (true)
{
cin >> sex;
if (sex == 1 || sex == 2)
{
abs->personArray.m_Sex = sex;
break;
}
else
{
cout << "您输入的有误,请重新输入" << endl;
break;
}
}
int age = 0;
cout << "请输入年龄" << endl;
while (true)
{
if (age < 100 && age >= 0)
{
abs->personArray.m_Age = age;
}
else
{
cout << "您输入的有误,请重新输入" << endl;
}
}
}
}
int main()
{
int select = 0;
struct Addressbooks abs;
abs.m_Size = 0;
while (true)
{
showMenu();
cin >> select;
switch (select)
{
case 1:
addPerson(&abs);
break;
case 2:
break;
case 3:
break;
case 4:
break;
case 5:
break;
case 6:
break;
case 0:
cout << "欢迎下次使用" << endl;
system("pause");
return 0;
break;
default:
break;
}
}
system("pause");
return 0;
}
其中如果我在if 和else 下加了break,效果运行有些不解，和
while (true)
{
cin >> sex;
if (sex == 1 || sex == 2)
{
abs->personArray.m_Sex = sex;
break;
}
cout << "输入有误,请重新输入" << endl;
}
cout << "请输入年龄" << endl;
int age = 0;
while (true)
{
cin >> age;
if (age <= 100 && age > 0)
{
abs->personArray.m_Age = age;
break;
}
cout << "输入有误,请重新输入" << endl;
}
中的循环语句if中加break有什么区别呢
本帖最后由 jackz007 于 2021-12-22 22:34 编辑
break 只与 for 、while 、switch ... case 三种结构语句有密切关系，而与 if 语句没有任何关系，没有必要把他们放在一起讨论。
break 语句的作用是跳出上述三种语句块，然后，从语句块之后的第一条语句开始继续执行。 我非常好奇，能够写出这样的代码，表示不是第一次写代码，为什么会问这个问题呢？
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