Written by

Namrata Jangid

### Without using an array

We add the numbers as and when the user enters them. For this logic, we will need a while or a for loop.

The code for adding n numbers using for loop is:

```#include <stdio.h>
int  main()
{
int  count;
int  num;
int  sum = 0;
int  i = 1;
printf("Enter the number of numbers you wish to add: ");
scanf("%d", & amp; count);
for  (i = 1; i & lt; = count; i++)
{
```  printf("Enter the number: ");

scanf("%d", & amp; num);

sum = sum + num;
```
}
printf("Sum: %d\n", sum);
return  0;
}```

The input and output for the above code is:

```Enter the number of numbers you wish to add:  2
Enter the number:  2
Enter the number:  2
Sum: 4
```
• We have created the variable count to store the number of numbers that the user wants to add.
• We have created the variable sum to store the sum of the numbers.
• We have created the variable i as a counter variable.
• We have created the variable num to store the number entered by the user in each iteration.
• In each iteration of the for loop, we are simply adding the number entered by the user.
• At the end of the for loop we get our total sum.

### Using an array

We can store the user input in an array and add the value present at each location in the array.

The code for adding n numbers using an array is:

```
#include <stdio.h>
int  main()
{
int  count;
int  sum = 0;
int  i = 1;
printf("Enter the number of numbers you wish to add: ");
scanf("%d", & amp; count);
int  arr[count];
for  (i = 1; i & lt; = count; i++) // for loop for storing user input in the array
{
```  printf("Enter a number: ");

scanf("%d", & amp; arr[i]);
```
}
for  (i = 1; i & lt; = count; i++) //for loop for calculating the sum
{
```  sum = sum + arr[i];
```
}
printf("Sum: %d\n", sum);
return  0;
}
```

The output for the above code is:

```
Enter the number of numbers you wish to add:  4
Enter a number:  1
Enter a number:  2
Enter a number:  3
Enter a number:  4
Sum: 10
```

• We have created the variable count to store the number of numbers that the user wants to add.
• We have created the variable sum to store the sum of the numbers.
• We have created the variable i as a counter variable.
• We have created the array arr to store the numbers entered by the user.
• In each iteration of the for loop, we are simply adding the number present at each index in the array.
• At the end of the for loop we get our total sum.