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cs:c_language:while_do-while_for_loops_1

# While, do-while and for loops (Example 1)

Concepts:
A simple example on the use of the loop constructs: `while`, `do-while` e `for`

Text:
Realize a program that:

• prints as output the numbers between `0` and `n`
• only `n>0` must be taken into account

Solution (while):

while_1.c
```/*
Realize a program that prints as output numbers between 0 and n (with n>0).
*/

#include <stdio.h>

int main()
{
unsigned int i, n;

printf("Number of elements: ");
scanf("%d", &n);

i=0;
while(i<=n){
printf("%3d\n", i);
i++;
}

return 0;
}```

Solution (do-while):

do-while_1.c
```/*
Realize a program that prints as output numbers between 0 and n (with n>0).
*/

#include <stdio.h>
int main()
{
unsigned int i, n;

printf("Number of elements: ");
scanf("%d", &n);

i=0;
do{
printf("%3d\n", i);
i++;
}while(i<=n);

return 0;
}```

Soluzione (for):

for_1.c
```/*
Realize a program that prints as output numbers between 0 and n (with n>0).
*/

#include <stdio.h>

int main()
{
unsigned int i=0, n;

printf("Number of elements: ");
scanf("%d", &n);

for(i=0;i<=n;i++){ /* This instruction can be equivalently written as for(;i<=n;i++), but only because the i variable has been initialized before */
printf("%3d\n", i);
}

return 0;
}``` 