Why do I get the right output but it also displays the if else output for program 2 and 3-CodePudding

This is a program for admission and there are certain conditions for each program

//The front
cout<<"Welcome to admission system"<<"\n";
cout<<"---------------------------"<<"\n";
cout<<"Admission open for year 2022"<<"\n";
cout<<"Press 1 for BSc Electrical Engineering Department"<<"\n";
cout<<"Press 2 for BSc Mechanical Engineering Department"<<"\n";
cout<<"Press 3 for MSc Mechanical Engineering Department"<<"\n";

//Personal details
cout<<"Your personal details"<<"\n";
cout<<"---------------------"<<"\n";
cout<<"Enter your Civil ID:";
cin>>civil_no;
cout<<"Enter your Name: ";
cin>>name;
cout<<"Enter Age: "<<"\n";
cin>>age;
cout<<"Enter contact Number: ";
cin>>phone;
cout<<"Enter program applying for: ";
cin>>pg; //pg here is meant as the department the user want to choose 

//Education details
cout<<"Education Details"<<"\n";
cout<<"-----------------"<<"\n";
cout<<"Enter Applicant highest qualification passing years:";
//cin>>year_of_passing;
cout<<"Enter Qualification Passing Year:";
//cin>>qualification;
cout<<"Enter Obtained marks (%):";
//cin>>marks;


//Program 1
if (pg==1 && marks>=60 && qualification==12) {
    cout<<"You are fully eligible for this program1"<<"\n";
}
else if(pg==1 || marks<60 || qualification!=12){
    cout<<"you are not eligible 1"<<"\n";
}


//Program 2
if (pg==2 && marks>=65 && qualification==12) {
    cout<<"You are fully eligible for this program 2"<<"\n";
}
else if(pg==2 || marks<65 || qualification!=12){
    cout<<"you are not eligible 2"<<"\n";
}


//Program 3
if (pg==3 && marks>=70 && qualification==14) {
    cout<<"You are fully eligible 3"<<"\n";
}
else if(pg==3 || marks<70 || qualification!=14){
    cout<<"you are not eligible 3"<<"\n";
}

CodePudding user response：

Whether pg==1 or 2 or 3, it can always enter the else condition of the other two programs. For eg, let's say: pg == 1 and marks= 62 and qualification = 12,

1. It will enter program 1's if block

//Program 1
if (pg==1 && marks>=60 && qualification==12) {
    cout<<"You are fully eligible for this program1"<<"\n";
}

2. It will enter program 2's else block

else if(pg==2 || marks<65 || qualification!=12){
    cout<<"you are not eligible 2"<<"\n";
}

3. It will enter program 3's else block

else if(pg==3 || marks<70 || qualification!=14){
    cout<<"you are not eligible 3"<<"\n";
}

This is because in the else block, you have used or || condition due to which even if one condition, (marks in this case) comes out to be true, the block will execute!!

CodePudding user response：

The set of if else statements is incorrect. For example if you entered a value of the qualification not equal to 12 then all three else statements will be executed because the condition qualification!=12 evaluates to true in all three else statements.

You need to write either

//Program 1
if (pg==1 && marks>=60 && qualification==12) {
    cout<<"You are fully eligible for this program1"<<"\n";
}
else if(pg==1 && ( marks<60 || qualification!=12 )){
    cout<<"you are not eligible 1"<<"\n";
}


//Program 2
if (pg==2 && marks>=65 && qualification==12) {
    cout<<"You are fully eligible for this program 2"<<"\n";
}
else if( pg==2 && ( marks<65 || qualification!=12 )){
    cout<<"you are not eligible 2"<<"\n";
}


//Program 3
if (pg==3 && marks>=70 && qualification==14) {
    cout<<"You are fully eligible 3"<<"\n";
}
else if( pg==3 && ( marks<70 || qualification!=14 ) ){
    cout<<"you are not eligible 3"<<"\n";
}

or for example

//Program 1
if ( pg==1 )
{ 
    if ( marks>=60 && qualification==12) {
        cout<<"You are fully eligible for this program1"<<"\n";
    }
    else {
        cout<<"you are not eligible 1"<<"\n";
    }
}


//Program 2
if (pg==2 )
{
    if ( marks>=65 && qualification==12) {
        cout<<"You are fully eligible for this program 2"<<"\n";
    }
    else {
        cout<<"you are not eligible 2"<<"\n";
    }
}


//Program 3
if ( pg==3 )
{
    if ( marks>=70 && qualification==14) {
        cout<<"You are fully eligible 3"<<"\n";
    }
    else {
        cout<<"you are not eligible 3"<<"\n";
    }
}