继承我的代码我试图整理上学,在嵌入式if和else if语句中,当我尝试编译时显示错误。
错误:在“else”之前期望primary-expression 预期';'在其他之前
这两个都出现在每一行。
// This is a program to Calculate the volume of the sphere using the radius (a03.cpp)
// Written by: Jimmy Scott
// Date: 2/1/12
// Sources: Stackoverflow.com (else and if statements)
#include <iomanip>
#include <iostream>
#include <string>
using namespace std;
int main ()
{
char vehicle;
float total;
char over20;
char old;
int adults;
int oldpass;
char height;
int youngpass;
int bicycles;
float length;
cout<<"Fare Calculator by Jimmy Scott";
cout<<"\n\n\n Are You Bringing a vehicle on The Ferry ?";
cin>>vehicle;
if (vehicle == 'y')
{
cout<<"\n\n"<<"Is the Driver over 65 Years of age or disabled?";
cin>>old;
cout<<"\n\n"<<"Passengers going along with the driver"<<"\n\n";
cout<<"Adults (19-64 Years old):";
cin>>adults;
cout<<"\n\n"<<"Senior Citizens or disabled:";
cin>>oldpass;
cout<<"\n\n"<<"Young passengers 5-18 years old: ";
cin>>youngpass;
cout<<"\n\n"<<"Is your Vehicle over 7ft, 6in in height? ";
cin>>height;
cout<<"Vehicle length in feet: ";
cin>>length;
if (old == 'y')
{
total= 44.60;
}
else if (old == 'n');
{
total= 51.20;
}
else if (length < 20) and (height == 'y');
{
total= 102.4;
}
else if (length > 20) and (length < 30);
{
total= 76.80;
}
else if (length > 20) and (length < 30) and (height = 'y');
{
total= 153.60;
}
else if (length > 30) and (length < 40);
{
total= 204.80;
}
}
else
{
cout<<"\n\n"<<"How many Senior Citizens or disabled are in your group?";
cin>>oldpass;
cout<<"\n\n"<<"How many adults are in your group?:";
cin>>adults;
cout<<"\n\n"<<"How many in your group are youths (5-18):";
cin>>youngpass;
cout<<"\n\n"<<"How many in your group have Bicycles:";
cin>>bicycles;
total=oldpass * 6.55;
total= total + (adults * 13.15);
total= total + (youngpass * 10.55);
total= total + (bicycles * 4.00);
}
cout<<"\n\n"<<"your total fare cost is : $"<<total;
cout<<"\n\n\n"<<"Press <Enter> to Exit";
cin.ignore();
cin.get();
return 0;
}
答案 0 :(得分:7)
有几件事:
当您执行条件时,不要直接使用分号进行测试,因为这会停止条件语句,并会执行与您想要的不同的操作。此外,由于它终止了if-else组,因此您将在下一个'else'语句中生成错误。
您还需要用括号括起条件测试。
以下是正确的else if语句的示例:
else if ((length > 30) and (length < 40))
{
total= 204.80;
}
更新:我最初说要使用&amp;&amp;而不是'和'。正如honk所说'和'在c ++中是一个有效的运算符,与&amp;&amp;相同。我更喜欢使用&amp;&amp;与c的便携性。
答案 1 :(得分:1)
消除所有';'在if else()语句之后。如果你有很多条件,也要添加'()'。