modular division

C Program To Reverse a Number

If a integer number is input through the keyboard, write a program to reverse the input number and display it on the console window.

For Example: If user enters 135, reversed number must be 531.

Note: We assign variable reverse = 0 to avoid garbage values in variable reverse.

Reversing a Number Logic

If user enters 456, we apply the modulo division to get the individual values.
Ex:
456 % 10 = 6
45 % 10 = 5
4 % 10 = 4

After each iteration of while loop we add the reminder to the previous value of variable reverse. We also multiply the variable reverse with 10, to increment the decimal place.

We get 456, 45 and 4 by dividing the original value by 10.
Ex:
456 user entered value.
456 / 10 = 45
45 / 10 = 4

Now the reverse:

reverse = (reverse * 10 ) + rem;

06 = (010) + 6
65 = (610) + 5
654 = (65*10) + 4

So finally the reversed number is 654.

Video Tutorial: C Program To Reverse a Number

[youtube https://www.youtube.com/watch?v=D8Yum35k6a0]

YouTube Link: https://www.youtube.com/watch?v=D8Yum35k6a0 [Watch the Video In Full Screen.]

Source Code: C Program To Reverse a Number

#include<stdio.h>

int main()
{
    int num, reverse = 0, rem;

    printf("Enter a integer number\n");
    scanf("%d", &num);

    while(num)
    {
        rem = num % 10;
        reverse = (reverse * 10) + rem;
        num     = num / 10;
    }

    printf("Reversed number is %d\n", reverse);

    return 0;
}

Output 1:
Enter a integer number
1023
Reversed number is 3201

Output 2:
Enter a integer number
159
Reversed number is 951

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For full C programming language free video tutorial list visit:C Programming: Beginner To Advance To Expert

Even or Odd Number using Ternary Operator and without using Modular Division: C Program

Today lets write a C program to check whether a user entered integer number is EVEN or ODD, without using modular division(%) operator and by using Ternary Operator / Conditional Operator.

Please visit the links I’ve posted above without fail before watching the video posted below.

Even or Odd Number: Source Code

 
#include < stdio.h >

int main()
{
    int n;

    printf("Enter a integer number\n");
    scanf("%d", &n);

    ( (n/2)*2 == n ) ?
    (printf("%d is Even\n", n)) :
    (printf("%d is Odd\n", n));


    return 0;
}

Output 1:
Enter a integer number
10
10 is Even

Output 2:
Enter a integer number
5
5 is Odd

Even or Odd Number using Ternary Operator and without using Modular Division: C Program

[youtube https://www.youtube.com/watch?v=4-AoNsgYJQ4]

YouTube Link: https://www.youtube.com/watch?v=4-AoNsgYJQ4 [Watch the Video In Full Screen.]

Note: Division of an integer number by 2(which is also an integer number) always returns integer number.

Example 1:
If user enters n = 2;
Applying n = 2 to ( (n/2)*2 == n ).
( (2/2)*2 == 2 )
( (1)*2 == 2 )
( 2 == 2 ) // true

So user entered value, that is, 2 is even number.

Example 2:
If user enters n = 3;
Applying n = 3 to ( (n/2)*2 == n ).
( (3/2)*2 == 3 )
( (1)*2 == 3 )
( 2 == 3 ) // false

2 is not equal to 3. So user entered value, that is, 3 is odd number.
In above example, 3/2 gives back 1 and not 1.5 as 3 is divided by integer which returns only the integer part and discards the decimal part.

For list of all c programming interviews / viva question and answers visit: C Programming Interview / Viva Q&A List

For full C programming language free video tutorial list visit:C Programming: Beginner To Advance To Expert

Even or Odd Number using Ternary Operator: C Program

Today lets write a C program to check whether a user entered integer number is EVEN or ODD, using Ternary / Conditional Operator.

Ternary Operator / Conditional Operator In C

Even or Odd Number: C Program

Even or Odd Number without using Modular Division: C Program

An even number is an integer that is exactly divisible by 2. An odd number is an integer that is not exactly divisible by 2.

C program To check Even or Odd Number using Ternary Operator

 
#include < stdio.h >

int main()
{
    int n;

    printf("Enter an integer number\n");
    scanf("%d", &n);

    (n % 2 == 0) ?
    (printf("%d is Even number\n", n)) :
    (printf("%d is Odd  number\n", n));

    return 0;
}

Output 1
Enter an integer number
2
2 is even number

Output 2
Enter an integer number
3
3 is odd number

Output 3
Enter an integer number
7
7 is odd number

Output 4
Enter an integer number
12
12 is even number

General Form of Ternary Operator

(expression_1) ? (expression_2) : (expression_3);

expression_1 is a comparison/conditional argument. expression_2 is executed/returned if expression_1 results in true, expression_3 gets executed/returned if expression_1 is false.

Even or Odd Number using Ternary Operator: C Program

[youtube https://www.youtube.com/watch?v=TMT53s8bhzQ]

YouTube Link: https://www.youtube.com/watch?v=TMT53s8bhzQ [Watch the Video In Full Screen.]

Modular division returns remainder of division. For example, 12 / 2 = 6. But 12 % 2 = 0.

In above c program, we ask the user to input an integer value and store it in variable n. Next using if else condition, we check if the user entered number is perfectly divisible by 2. If its perfectly divisible by 2, then it’e even number or else its odd number.

For list of all c programming interviews / viva question and answers visit: C Programming Interview / Viva Q&A List

For full C programming language free video tutorial list visit:C Programming: Beginner To Advance To Expert

Assignment Operators in C

In this video tutorial we show Compound Assignment Operators in C programming language.

Related Read:
Simple Calculator Application In C

Assignment Operators

If a and c are the operands.

c += a; is equal to writing c = c + a;
c -= a; is equal to writing c = c – a;
c *= a; is equal to writing c = c * a;
c /= a; is equal to writing c = c / a;
c %= a; is equal to writing c = c % a;

Assignment Operator +=

 
#include < stdio.h >

int main()
{
    int a = 20, c = 30;

    c += a ; // c = c + a;

    printf("%d\n\n", c);

    return 0;
}

Output:
50

Assignment Operator -=

 
#include < stdio.h >

int main()
{
    int a = 20, c = 30;

    c -= a ; // c = c - a;

    printf("%d\n\n", c);

    return 0;
}

Output:
10

Assignment Operator *=

 
#include < stdio.h >

int main()
{
    int a = 20, c = 30;

    c *= a ; // c = c * a;

    printf("%d\n\n", c);

    return 0;
}

Output:
600

Assignment Operator /=

 
#include < stdio.h >

int main()
{
    int a = 2, c = 20;

    c /= a ; // c = c / a;

    printf("%d\n\n", c);

    return 0;
}

Output:
10

Assignment Operator %=

 
#include < stdio.h >

int main()
{
    int a = 2, c = 20;

    c %= a ; // c = c % a;

    printf("%d\n\n", c);

    return 0;
}

Output:
0

Compound Assignment Operators in C Programming Language

[youtube https://www.youtube.com/watch?v=-_ZBdT2Yxqo]

YouTube Link: https://www.youtube.com/watch?v=-_ZBdT2Yxqo [Watch the Video In Full Screen.]

You can also learn about Logical and Relational Operators in C:
Relational Operators In C
Logical Operators In C

For list of all c programming interviews / viva question and answers visit: C Programming Interview / Viva Q&A List

For full C programming language free video tutorial list visit:C Programming: Beginner To Advance To Expert

Even or Odd Number without using Modular Division: C Program

Today lets write a C program to check whether a user entered integer number is EVEN or ODD, without using modular division(%) operator.

Related Read:
Even or Odd Number: C Program (using Modular Division Operator)
Basic Arithmetic Operations In C
Relational Operators In C

An even number is an integer that is exactly divisible by 2. An odd number is an integer that is not exactly divisible by 2.

Note:
1. Even numbers are of the form 2 * n;
2. Odd numbers are of the form (2 * n + 1);

You can substitute n value in above forms and check the resulting numbers for even or odd.

Even or Odd Number: Source Code

 
#include < stdio.h >

int main()
{
    int n;

    printf("Enter an integer number\n");
    scanf("%d", &n);

    if( (n/2)*2 == n )
    {
        printf("%d is even number\n", n);
    }
    else
    {
        printf("%d is odd number\n", n);
    }

    return 0;
}

Output 1
Enter an integer number
2
2 is even number

Output 2
Enter an integer number
3
3 is odd number

Output 3
Enter an integer number
7
7 is odd number

Output 4
Enter an integer number
12
12 is even number

C Program To Check Even or Odd Number, without using Modular Division Operator

[youtube https://www.youtube.com/watch?v=qc-wK_amMzs]

YouTube Link: https://www.youtube.com/watch?v=qc-wK_amMzs [Watch the Video In Full Screen.]

Note: Division of an integer number by 2(which is also an integer number) always returns integer number.

In above c program, we ask the user to input an integer value and store it in variable n. Next using if else condition, we check if the user entered number is even or odd.

User entered integer number is divided by 2. And then it is multiplied by 2. If the final result is equal to the original user entered value, then the user entered value is even orelse its odd.

Example 1:
If user enters n = 2;
Applying n = 2 to ( (n/2)*2 == n ).
( (2/2)*2 == 2 )
( (1)*2 == 2 )
( 2 == 2 ) // true

So user entered value, that is, 2 is even number.

Example 2:
If user enters n = 3;
Applying n = 3 to ( (n/2)*2 == n ).
( (3/2)*2 == 3 )
( (1)*2 == 3 )
( 2 == 3 ) // false

For full C programming language free video tutorial list visit:C Programming: Beginner To Advance To Expert