c++day-15
TRANSCRIPT
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[ Binary ]
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Explain Binary file
Random access File modes
Modifying,Deleting,viewing record in a file
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#include#include#include#include
class employee{
private:int eno;char ename[20];float basic,pf,hra,net;
public:void new_employee();void del_employee();void show_employee();
void modify_employee();};
void employee::new_employee() {fstream f
char wish;int lastno;
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do{
f.open("emp.dat",ios::in|ios::binary);f.seekg(0,ios::end);if(f.tellg()==0)lastno=1;else{
f.seekg(f.tellg()-sizeof(employee),ios::beg);f.read((char *)this,sizeof(employee));
lastno=eno+1;}f.seekg(0,ios::end);eno=lastno;cout
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couthra;net=basic+pf+hra;f.write((char *)this,sizeof(employee));f.close();
coutwish;
}while(wish=='y');
}void employee::del_employee(){
fstream f1,f2;char wish;int no,found;do
{found=0;f1.open("emp.dat",ios::in);f2.open("temp.dat",ios::out);coutno;
f1.read((char *)this,sizeof(employee));
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while(!f1.eof()){if(eno==no)found=1;
elsef2.write((char *)this,sizeof(employee));f1.read((char *)this,sizeof(employee));}if(!found)cout
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do{found=0;coutno;
f.open("emp.dat",ios::in);f.read((char *)this,sizeof(employee));while(!f.eof()) {if(eno==no){found=1;
cout
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void employee::modify_employee(){fstream f;int no,found;char wish;
do{found=0;f.open("emp.dat",ios::in);coutno;
f.read((char *)this,sizeof(employee));while(!f.eof()){if(eno==no){found=1;
cout
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net=basic+pf+hra;f.seekp(f.tellg()-sizeof(employee)),ios::beg;f.write((char *)this,sizeof(employee));}f.read((char *)this,sizeof(employee));
}if(!found)cout
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cout
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To write and read the contents in afile we must create an object
of class ofstream & ifstream
The open() function is used to open different files that uses the
same stream object
The close() function is used to close a file. It takes no parameters
and returns no value
The put() function is used for writing one character at a time in
a file
The get() function is used for reading one charater at a time
from a file
The write() function is member function of the ofstream class
which writes text in a line until it encounters a new line character
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