C++ 如何初始化已传递的结构变量?
好的,所以我们必须把这个程序从读取用户输入改为从文件中读取,到目前为止,我已经修改了一段代码,这段代码将从文件中读取,但每次我运行代码时,我都会发现这5个错误,我无法理解,所以这是我的代码C++ 如何初始化已传递的结构变量?,c++,io,project,C++,Io,Project,好的,所以我们必须把这个程序从读取用户输入改为从文件中读取,到目前为止,我已经修改了一段代码,这段代码将从文件中读取,但每次我运行代码时,我都会发现这5个错误,我无法理解,所以这是我的代码 // Author: // Source file: // Description: // Compiler used: #include <iostream> #include <iomanip> #include <fstream> using
// Author:
// Source file:
// Description:
// Compiler used:
#include <iostream>
#include <iomanip>
#include <fstream>
using namespace std;
struct records
{
int code;
double amount;
};
// Function Prototypes
void displayTitle();
double getBegBal(ifstream&);
void displayBal(records);
records getData(ifstream&);
double processCheck(double, double);
double processDeposit(double, double);
double processATM(double, double);
double processSvcChg(double);
//Global Constants
const double CHARGE = 10,
ATMFEE = 2;
int main()
{
//Variable Declarations
int transCode;
double balance,
transAmt;
cout.setf(ios::fixed);
cout.setf(ios::showpoint);
cout.precision(2);
records trans;
ifstream inFile;
inFile.open("c:\\checkIn.dat");
displayTitle();
balance = getBegBal(inFile);
getData(inFile);
while (!inFile.eof())
{
trans = getData(inFile);
switch (trans.code)
{
case 1: balance = processCheck(balance, trans.amount); break;
case 2: balance = processDeposit(balance, trans.amount); break;
case 3: balance = processATM(balance, trans.amount); break;
}
displayBal(trans);
if (balance < 0)
balance = processSvcChg(balance);
getData(inFile);
}
return 0;
}
void displayTitle()
{
cout << "\n Check Register\n\n";
}
double getBegBal(ifstream& inFile)
{
//double bal;
records balance;
cout << " Enter beginning balance ";
inFile >> balance.amount;
return balance.amount;
}
void displayBal(records balance)
{
cout << "\t\tBalance = $" << setw(10) << balance.amount;
}
records getData(ifstream& inFile)
{
records rec;
cout << "\n\n Enter transaction code (0 to exit) ";
inFile >> rec.code;
if (rec.code > 0)
{
cout << "\n Enter transaction amount ";
}
return rec;
}
double processCheck(double bal, double amt)
{
cout << "\n Check = " << setw(10) << amt;
return (bal - amt);
}
double processDeposit(double bal, double amt)
{
cout << "\n Deposit = " << setw(10) << amt;
return (bal + amt);
}
double processATM(double bal, double amt)
{
records trans;
cout << "\n ATM = " << setw(10) << trans.amount;
bal = bal - amt;
displayBal(trans);
bal = bal - ATMFEE;
cout << "\n ATM Fee = " << setw(10) << ATMFEE;
return (bal);
}
double processSvcChg(double bal)
{
records trans;
cout << "\n Service chg =" << setw(8) << CHARGE;
bal = bal - CHARGE;
displayBal(trans);
return (bal);
}
错误为“transCode”:未引用的局部变量和
“transAmt”:未引用的局部变量
错误4-5在这里
int transCode;
double balance,
transAmt;
double processATM(double bal, double amt)
{
records trans;
cout << "\n ATM = " << setw(10) << trans.amount;
bal = bal - amt;
displayBal(trans);// the error points here saying that the variable trans is uninitialized
bal = bal - ATMFEE;
cout << "\n ATM Fee = " << setw(10) << ATMFEE;
return (bal);
}
double processSvcChg(double bal)
{
records trans;
cout << "\n Service chg =" << setw(8) << CHARGE;
bal = bal - CHARGE;
displayBal(trans); // the error points here saying that the variable trans is uninitialized
return (bal);
}
双流程ATM(双倍余额,双倍金额)
{
记录转换;
无法您初始化了width=0;
并将其传递给getWidth()
。因此,width%2!=0
将被评估为false,并且getWidth()
中的提示将不会显示
getWidth()
不需要任何参数,除非您的赋值需要它,因为它只是用来读取宽度并重新填充
do
语句用于在执行一次循环体后评估条件
int getWidth()
{
int width = 0;
do {
cout << "Enter width " << endl;
cin >> width;
} while (width % 2 != 0);
return width;
}
这对我有用
int displayMenu();
void displaySquare(int width);
void displayTriangle(int width);
int getWidth();
void displayUpsideDownTriangle(int width);
void displayDiamond(int width);
int main()
{
int width, shapes;
do {
shapes = displayMenu();
width = 0;
switch (shapes)
{
case 1:
width = getWidth();
displaySquare(width);
break;
case 2:
width = getWidth();
displayTriangle(width);
break;
case 3:
width = getWidth();
displayUpsideDownTriangle(width);
break;
case 4:
width = getWidth();
displayDiamond(width);
break;
case -9:
cout << "End of Program " << endl;
default:
cout << "Please choose one of the shapes..." << endl;
}
} while (shapes != -9);
system("pause");
return 0;
}
//this function sets up the display for the user
int displayMenu() {
int shapes;
cout << "\n~~ Shape Display menu ~~ " << endl << endl;
cout << " 1....Square\n" <<
" 2....Triangle\n " <<
" 3....Upside Down triangle\n " <<
" 4....Diamond\n\n " <<
" -9....Exit Program " << endl;
cout << endl;
cout << " Make a selection " << endl;
cin >> shapes;
return shapes;
}
int getWidth()
{
int width = 1;
do {
if (width % 2 != 0)
{
cout << "Enter width " << endl;
cin >> width;
}
else
{
cout << "Please enter odd number only. \nEnter width " << endl;
cin >> width;
}
} while (width % 2 == 0);
return width;
}
void displaySquare(int width)
{
int rows, columns;
for (rows = 0; rows < width; ++rows)
{
for (columns = 0; columns < width; ++columns)
{
cout << "# ";
}
cout << endl;
}
}
void displayTriangle(int width)
{
int rows, Spacing, ColHashtag;
for (rows = 1; rows < width; rows++) //controls the rows
{
for (Spacing = (width - rows); Spacing >= 1; Spacing--) // spaces out the rows to make an isoceles triangle
{
cout << " ";
}
for (ColHashtag = 1; ColHashtag <= (rows * 2) - 1; ColHashtag++) //controls the columns
{
cout << "#";
}
cout << endl;
}
}
void displayUpsideDownTriangle(int width)
{
int rows, Columns, spacing;
//sets up the rows for the top
for ((rows = width - 1); rows >= 1; rows--)
{
for (Columns = 1; Columns <= width - rows; Columns++) // sets up the columns
{
cout << " "; // spaces out the symbols to make an isoceles triangle
}
for (spacing = 1; spacing <= 2 * rows - 1; spacing++)
{
cout << "#";
}
cout << endl;
}
}
void displayDiamond(int width)
{
displayTriangle(width);
displayUpsideDownTriangle(width);
}
int displayMenu();
空白显示正方形(整数宽度);
空白显示三角形(整数宽度);
int getWidth();
void displayUpsideDownTriangle(内部宽度);
空白显示菱形(整数宽度);
int main()
{
int宽度、形状;
做{
形状=显示菜单();
宽度=0;
开关(形状)
{
案例1:
宽度=getWidth();
显示正方形(宽度);
打破
案例2:
宽度=getWidth();
显示三角形(宽度);
打破
案例3:
宽度=getWidth();
显示UpsideDownTriangle(宽度);
打破
案例4:
宽度=getWidth();
显示菱形(宽度);
打破
案例9:
cout将int main()和getWidth()替换为
int main()
{
int width, shapes,wt;
do {
cout << "Enter width " << endl;
cin >> width;
wt=getWidth(width);
if(wt!=0)
{
shapes = displayMenu();
}
else
{
shapes=-9;
}
switch (shapes)
{
case 1:
displaySquare(wt);
break;
case 2:
displayTriangle(wt);
break;
case 3:
displayUpsideDownTriangle(wt);
break;
case 4:
displayDiamond(wt);
break;
case -9:
cout << "End of Program " << endl;
break;
default:
cout << "Please choose one of the shapes..." << endl;
}
} while (shapes != -9);
system("pause");
return 0;
}
int getWidth(int width)
{
while (width % 2 != 0) {
cout << "Enter width " << endl;
cin >> width;
}
return width;
}
intmain()
{
int宽度、形状、wt;
做{
库特宽度;
wt=getWidth(宽度);
如果(wt!=0)
{
形状=显示菜单();
}
其他的
{
形状=-9;
}
开关(形状)
{
案例1:
显示广场(wt);
打破
案例2:
显示三角形(wt);
打破
案例3:
显示UpsideDownTriangle(wt);
打破
案例4:
显示钻石(wt);
打破
案例9:
您能告诉我为什么需要在getWidth函数中循环获取宽度吗?getWidth()
返回读取的宽度,然后将其丢弃。捕获它!此函数显示提示,请求宽度值,并返回宽度整数值。宽度必须是奇数,因此,如果输入的不是奇数,则向用户显示错误消息,并请求有效的输入。循环直到输入奇数。不要如果菜单选择为-9或选择无效,则从main调用此函数。@DaoXio此函数显示一条提示,要求输入宽度值,并返回宽度的整数值。宽度必须是奇数,因此如果输入不是奇数,则向用户显示错误消息,并请求有效输入。循环直到输入了一个奇数。如果菜单选择为-9或选择无效,请不要从main调用此函数。如果我这样做,则我必须重做所有调用width的函数。这就是答案。您将只更改getWidth()函数。将原型从int getWidth(int width);
更改为int getWidth()
好的,我试过了,程序甚至没有运行,它给出了以下错误:etwidth:function对所有四个shapes@BartholomewAllen请将getWidth()
的用法更改为我所写的用法。好的,现在我明白你的意思了!谢谢!它可以工作了!:D
int main()
{
int width, shapes,wt;
do {
cout << "Enter width " << endl;
cin >> width;
wt=getWidth(width);
if(wt!=0)
{
shapes = displayMenu();
}
else
{
shapes=-9;
}
switch (shapes)
{
case 1:
displaySquare(wt);
break;
case 2:
displayTriangle(wt);
break;
case 3:
displayUpsideDownTriangle(wt);
break;
case 4:
displayDiamond(wt);
break;
case -9:
cout << "End of Program " << endl;
break;
default:
cout << "Please choose one of the shapes..." << endl;
}
} while (shapes != -9);
system("pause");
return 0;
}
int getWidth(int width)
{
while (width % 2 != 0) {
cout << "Enter width " << endl;
cin >> width;
}
return width;
}