💻 if else Statement in C++ Example Program

if else statement in c++ sample problems

C++ check whether a character is alphabet or not

In this program, we are going to see whether a user given character is an alphabet or not. To determine the type of character, we have to check it’s ASCII value range.


#include <iostream>

using namespace std;

int main() {

    char ch;
        
    cout << "Enter any character: ";
    cin >> ch;
    
    if((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z')) {

        cout << endl << ch << " is ALPHABET.";

    } else {

        cout << endl<< ch << " is NOT ALPHABET.";

    }

    return 0;
}

#include <iostream>

using namespace std;

int main() {

char ch;

cout << "Enter any character: ";

cin >> ch;

if((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z')) {

cout << endl << ch << " is ALPHABET.";

} else {

cout << endl<< ch << " is NOT ALPHABET.";

}

return 0;

}

Output:


Enter any character : x
x is ALPHABET.

Enter any character : x

x is ALPHABET.

C++ check whether a character is alphabet, digit or special character

This program is much similar to the previous one but here we are checking whether the given character is an alphabet, digit or a special character.


#include <iostream>

using namespace std;

int main() {

    char ch;

    cout << "Enter any character : ";
    cin >> ch;

    if((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z')) {

        cout << endl << ch << " is ALPHABET.";

    } else if(ch >= '0' && ch <= '9') {

        cout << endl << ch << " is DIGIT.";

    } else {

        cout << endl << ch << " is SPECIAL CHARACTER.";

    }

    return 0;
}

#include <iostream>

using namespace std;

int main() {

char ch;

cout << "Enter any character : ";

cin >> ch;

if((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z')) {

cout << endl << ch << " is ALPHABET.";

} else if(ch >= '0' && ch <= '9') {

cout << endl << ch << " is DIGIT.";

} else {

cout << endl << ch << " is SPECIAL CHARACTER.";

}

return 0;

}

Output:


Enter any character : #
# is SPECIAL CHARACTER.

Enter any character : #

# is SPECIAL CHARACTER.

C++ find largest number among three number using if statement

In this program, we are going to see how to find the largest number among three numbers using if statement.

Logic

Here we have to compare each number with another two numbers, if it is greater than the both then simply print it.

Let’s say A = 11, B = 22 and C = 15

Then steps would be

if A > B and A > C that means A is the largest number.
if B > A and B > C that means B is the largest number.
Similarly if C > A and C > B that means C is the largest number.


#include <iostream>

using namespace std;

int main() {

    float num1, num2, num3;

    cout << "Enter 1st number : ";
    cin >> num1;

    cout << endl << "Enter 2nd number : ";
    cin >> num2;

    cout << endl<< "Enter 3rd number : ";
    cin >> num3;

    if(num1 >= num2 && num1 >= num3) {

        cout << endl << num1 << " is largest number";

    } 

    if(num2 >= num1 && num2 >= num3) {
        
        cout << endl << num2 << " is largest number";

    }

    if(num3 >= num1 && num3 >= num2) {

        cout << endl << num3 << " is largest number";
    }

    return 0;
}

#include <iostream>

using namespace std;

int main() {

float num1, num2, num3;

cout << "Enter 1st number : ";

cin >> num1;

cout << endl << "Enter 2nd number : ";

cin >> num2;

cout << endl<< "Enter 3rd number : ";

cin >> num3;

if(num1 >= num2 && num1 >= num3) {

cout << endl << num1 << " is largest number";

}

if(num2 >= num1 && num2 >= num3) {

cout << endl << num2 << " is largest number";

}

if(num3 >= num1 && num3 >= num2) {

cout << endl << num3 << " is largest number";

}

return 0;

}

Output:


Enter 1st number : 10
Enter 2nd number : 5
Enter 3rd number : 11
11 is largest number

Enter 1st number : 10

Enter 2nd number : 5

Enter 3rd number : 11

11 is largest number

C++ find largest number among three number using if else statement

This program is similar to the previous one, with a single modification, here we will use if else statement to find the largest number.

Logic

The logic to find the largest number among the three numbers, we have to compare each number with the other two numbers.

Let three variables be: A = 400, B = 200 and C = 300

if A > B and A > C, then print A.
else if B > A and B > C, then print B.
else print C.


#include <iostream>

using namespace std;

int main() {

    float num1, num2, num3;

    cout << "Enter 1st number : ";
    cin >> num1;

    cout << endl << "Enter 2nd number : ";
    cin >> num2;

    cout << endl << "Enter 3rd number : ";
    cin >> num3;

    if(num1 >= num2 && num1 >= num3) {

        cout << endl << num1 << " is largest number";

    } else if(num2 >= num3) {
        
        cout << endl << num2 << " is largest number";

    } else {

        cout << endl << num3 << " is largest number";
    }

    return 0;
}

#include <iostream>

using namespace std;

int main() {

float num1, num2, num3;

cout << "Enter 1st number : ";

cin >> num1;

cout << endl << "Enter 2nd number : ";

cin >> num2;

cout << endl << "Enter 3rd number : ";

cin >> num3;

if(num1 >= num2 && num1 >= num3) {

cout << endl << num1 << " is largest number";

} else if(num2 >= num3) {

cout << endl << num2 << " is largest number";

} else {

cout << endl << num3 << " is largest number";

}

return 0;

}

Output:


Enter 1st number : 10
Enter 2nd number : 200
Enter 3rd number : 11
200 is largest number

Enter 1st number : 10

Enter 2nd number : 200

Enter 3rd number : 11

200 is largest number

C++ find largest number among three number using nested if else statement

In this program, we are going to find the largest number among three numbers, similar to the previous one, but it is nested if-else version.

Logic

Let three variables be: A = 400, B = 200 and C = 300

The logic goes like this:

if A >= B then check for if A >= C, then print A else print C.
else part: if B >= C then print B else print C.


#include <iostream>

using namespace std;

int main() {

    float num1, num2, num3;

    cout << "Enter 1st number : ";
    cin >> num1;

    cout << endl << "Enter 2nd number : ";
    cin >> num2;

    cout << endl << "Enter 3rd number : ";
    cin >> num3;

    if(num1 >= num2) {

        if(num1 >= num3) {
            cout << endl << num1 << " is largest number";
        } else {
            cout << endl << num3 << " is largest number";
        }
        
    } else {

        if(num2 >= num3) {
            cout << endl << num2 << " is largest number";
        } else {
            cout << endl << num3 << " is largest number";
        }

    }

    return 0;
}

#include <iostream>

using namespace std;

int main() {

float num1, num2, num3;

cout << "Enter 1st number : ";

cin >> num1;

cout << endl << "Enter 2nd number : ";

cin >> num2;

cout << endl << "Enter 3rd number : ";

cin >> num3;

if(num1 >= num2) {

if(num1 >= num3) {

cout << endl << num1 << " is largest number";

} else {

cout << endl << num3 << " is largest number";

}

} else {

if(num2 >= num3) {

cout << endl << num2 << " is largest number";

} else {

cout << endl << num3 << " is largest number";

}

return 0;

}

Output


Enter 1st number : 100
Enter 2nd number : 10
Enter 3rd number : 99
100 is largest number

Enter 1st number : 100

Enter 2nd number : 10

Enter 3rd number : 99

100 is largest number

C++ program to check whether a year is leap year or not

Leap year

A leap year is a calendar year that includes an additional day to synchronize the calendar year with the astronomical or seasonal year. – Wikipedia

Logic

The Logic to check this is quite simple. We only need to check if the given year is multiple of 4 or 400, but it should not be multiple of 100.


#include <iostream>

using namespace std;

int main() {

    int year;

    cout << "Enter a year : ";
    cin >> year;

    if (year % 4 == 0) {

        if (year % 100 == 0) {

            if (year % 400 == 0) {
                cout << endl << year << " is a leap year.";
            } else {
                cout << endl << year << " is not a leap year.";
            }
                
        } else {
            cout << endl << year << " is a leap year.";
        }

    } else {
        cout << endl << year << " is not a leap year.";
    }

    return 0;
}

#include <iostream>

using namespace std;

int main() {

int year;

cout << "Enter a year : ";

cin >> year;

if (year % 4 == 0) {

if (year % 100 == 0) {

if (year % 400 == 0) {

cout << endl << year << " is a leap year.";

} else {

cout << endl << year << " is not a leap year.";

}

} else {

cout << endl << year << " is a leap year.";

}

} else {

cout << endl << year << " is not a leap year.";

}

return 0;

}

Output


Enter a year : 2012
2012 is a leap year.

Enter a year : 2012

2012 is a leap year.

C++ program to check whether number is even or odd

Even number

Even numbers are numbers that have a difference of 2 unit or number. In other words, if the number is completely divisible by 2 then it is an even number.

Odd number

Opposite of even numbers, odd numbers are having a difference of 3 unit or number. In other words, if the number is not completely divisible by 2 then it is an odd number.

Logic

To find if a number is even or odd we only need to check if the given number is multiple of 2 or not, If it is multiple of 2 that means it is even number otherwise an odd number.

To check if it is multiple of 2 or not we use modulus operator.

If the expression number % 2 returns 0 that means the number is a multiple of 2. In other words, it is completely divisible by 2.


#include <iostream>

using namespace std;

int main() {

    int number;

    cout << "Enter an integer : ";
    cin >> number;

    if (number % 2 == 0) {
        cout << endl << number << " is even number.";
    } else {
        cout << endl << number << " is odd number.";
    }

    return 0;
}

#include <iostream>

using namespace std;

int main() {

int number;

cout << "Enter an integer : ";

cin >> number;

if (number % 2 == 0) {

cout << endl << number << " is even number.";

} else {

cout << endl << number << " is odd number.";

}

return 0;

}

Output


Enter an integer : 886
886 is even number.

Enter an integer : 886

886 is even number.

C++ check whether a number is negative, positive or zero

Positive number

All the numbers greater than 0, but not equal to 0 are positive numbers.

Negative number

Similarly all the number less than 0, but not equal to 0 are negative numbers.

Logic

If the number is greater than zero that means it is positive. If the number is less than zero that means it is negative. If the number is equal to zero that means it is absolute zero.

if number > 0 then print Positive.
if number < 0 then print Negative.
if number == 0 then print Zero.


#include <iostream>

using namespace std;

int main() {

    int number;
    
    cout << "Enter any number : ";
    cin >> number;

    if(number > 0) {
        cout << endl << "POSITIVE NUMBER" << endl;
    }

    if(number < 0) {
        cout << endl << "NEGATIVE NUMBER" << endl;
    }

    if(number == 0) {
        cout << endl << "NUMBER IS ZERO" << endl;
    }

    return 0;
}

#include <iostream>

using namespace std;

int main() {

int number;

cout << "Enter any number : ";

cin >> number;

if(number > 0) {

cout << endl << "POSITIVE NUMBER" << endl;

}

if(number < 0) {

cout << endl << "NEGATIVE NUMBER" << endl;

}

if(number == 0) {

cout << endl << "NUMBER IS ZERO" << endl;

}

return 0;

}

Output


Enter any number : 101
POSITIVE NUMBER.

Enter any number : 101

POSITIVE NUMBER.

C++ check whether a character is upper or lowercase alphabet

If the ASCII value of a character lies between 65 (A) to 90 (Z) then it is an uppercase character or if the character’s ASCII value lies between 97 (a) to 122 (z) then it is a lowercase character.


#include <iostream>

using namespace std;

int main() {

    char ch;

    cout << "Enter any character : ";
    cin >> ch;

    if(ch >= 'A' && ch <= 'Z') {

        cout << endl << ch << " is UPPERCASE alphabet.";

    } else if(ch >= 'a' && ch <= 'z') {

        cout << endl << ch << " is LOWERCASE alphabet.";

    } else {

        cout << endl << ch << " is not an alphabet.";

    }

    return 0;
}

#include <iostream>

using namespace std;

int main() {

char ch;

cout << "Enter any character : ";

cin >> ch;

if(ch >= 'A' && ch <= 'Z') {

cout << endl << ch << " is UPPERCASE alphabet.";

} else if(ch >= 'a' && ch <= 'z') {

cout << endl << ch << " is LOWERCASE alphabet.";

} else {

cout << endl << ch << " is not an alphabet.";

}

return 0;

}

Output


Enter any character : S
S is UPPERCASE alphabet.

Enter any character : S

S is UPPERCASE alphabet.

C++ check whether a character is vowel or consonant

There are five vowel characters {a, e, i, o, u}. If the user given character input is one of them that means it is a vowel otherwise it is a consonant.

Logic

Here we have to manually check the given character with all the vowel characters, we cannot use ASCII value range to determine whether it is a vowel or a consonant. The given character can also be in the form of uppercase.


#include <iostream>

using namespace std;

int main() {

    char c;   

    cout << "Enter a alphabet : ";
    cin >> c;

    // if given character is Lower case Vowel or Upper case Vowel
    // then print vowel otherwise consonant
    if ((c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u') 
        || (c == 'A' || c == 'E' || c == 'I' || c == 'O' || c == 'U')) {

        cout << endl << c << " is a vowel.";

    } else{

        cout << endl << c << " is a consonant.";

    }

    return 0;
}

#include <iostream>

using namespace std;

int main() {

char c;

cout << "Enter a alphabet : ";

cin >> c;

// if given character is Lower case Vowel or Upper case Vowel

// then print vowel otherwise consonant

if ((c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u')

|| (c == 'A' || c == 'E' || c == 'I' || c == 'O' || c == 'U')) {

cout << endl << c << " is a vowel.";

} else{

cout << endl << c << " is a consonant.";

}

return 0;

}

Output


Enter a alphabet : A
A is a vowel.

Enter a alphabet : A

A is a vowel.

C++ print day name of week from number

In this program, we are going to print day name based on week no. Like – If the user enters 1 that means it is Monday.

Logic

After taking input (Week no) from the user, we have to compare that number with 1 to 7 or we can say comparing that number with a day of a week. So the logic goes like – if the number is equal to 1 then it is Monday, if the number is 2 then it is Tuesday etc… Like that we have to compare with each day of the week.


#include <iostream>

using namespace std;

int main() {

    int weekday;

    cout << "Enter weekday day number (1-7) : ";
    cin >> weekday;

    if(weekday == 1) {

        cout << endl << "Monday";

    } else if(weekday == 2) {

        cout << endl << "Tuesday";

    } else if(weekday == 3) {

        cout << endl << "Wednesday";

    } else if(weekday == 4) {

        cout << endl << "Thursday";

    } else if(weekday == 5) {

        cout << endl << "Friday";

    } else if(weekday == 6) {

        cout << endl << "Saturday";

    } else if(weekday == 7) {

        cout << endl << "Sunday";

    } else {

        cout << endl << "Please enter weekday number between 1-7.";
    }
   
    return 0;
}

#include <iostream>

using namespace std;

int main() {

int weekday;

cout << "Enter weekday day number (1-7) : ";

cin >> weekday;

if(weekday == 1) {

cout << endl << "Monday";

} else if(weekday == 2) {

cout << endl << "Tuesday";

} else if(weekday == 3) {

cout << endl << "Wednesday";

} else if(weekday == 4) {

cout << endl << "Thursday";

} else if(weekday == 5) {

cout << endl << "Friday";

} else if(weekday == 6) {

cout << endl << "Saturday";

} else if(weekday == 7) {

cout << endl << "Sunday";

} else {

cout << endl << "Please enter weekday number between 1-7.";

}

return 0;

}

Output


Enter weekday day number (1-7) : 4
Thursday

Enter weekday day number (1-7) : 4

Thursday

if else statement in c++ sample problems

C++ check whether a character is alphabet or not

C++ check whether a character is alphabet, digit or special character

C++ find largest number among three number using if statement

C++ find largest number among three number using if else statement

C++ find largest number among three number using nested if else statement

C++ program to check whether a year is leap year or not

C++ program to check whether number is even or odd

C++ check whether a number is negative, positive or zero

C++ check whether a character is upper or lowercase alphabet

C++ check whether a character is vowel or consonant

C++ print day name of week from number

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