In this post, we will learn how to display prime numbers between intervals using functions in the C Programming language.
As we know, Prime Numbers are the whole numbers greater than 1 and have only two factors – 1 and itself. For example: 2, 3, 5, 7 and so on.
We will be writing a program which will display prime numbers lying in a given range using functions.
So, without further ado, let’s begin this tutorial.
C Program to Display Prime Numbers Between Intervals Using Function
// C Program to Display Prime Numbers Between Intervals Using Function #include <stdio.h> int checkPrime(int n); int main(){ int lowerlimit, upperlimit, i, flag; // Asking for Input printf("Enter the lower limit: "); scanf("%d", &lowerlimit); printf("Enter the upper limit: "); scanf("%d", &upperlimit); printf("Prime Numbers Between %d and %d are: \n", lowerlimit, upperlimit); for (i = lowerlimit + 1; i < upperlimit; ++i){ flag = checkPrime(i); if (flag == 1){ printf("%d\t", i); } } return 0; } int checkPrime(int n){ int j, flag = 1; for (j = 2; j <= n / 2; ++j){ if (n % j == 0){ flag = 0; break; } } return flag; }
Output
Enter the lower limit: 5
Enter the upper limit: 25
Prime Numbers Between 5 and 25 are:
7 11 13 17 19 23
How Does This Program Work ?
int lowerlimit, upperlimit, i, flag;
In this program, we have declared four int data type variables named as lowerlimit, upperlimit, i and flag.
// Asking for Input
printf("Enter the lower limit: ");
scanf("%d", &lowerlimit);
printf("Enter the upper limit: ");
scanf("%d", &upperlimit);
Then, the user is asked to enter the range, for example: the lower and upper limit of the range.
int checkPrime(int n){
int j, flag = 1;
for (j = 2; j <= n / 2; ++j){
if (n % j == 0){
flag = 0;
break;
}
}
return flag;
}
We have defined a custom function named checkPrime which will check whether a particular value is prime or not.
for (i = lowerlimit + 1; i < upperlimit; ++i){
flag = checkPrime(i);
if (flag == 1){
printf("%d\t", i);
}
}
We import this custom function in the main function which checks whether different iterations of i are prime or not.
If yes, then we will print it otherwise we will just ignore it.
Conclusion
I hope after going through this post, you understand how to display prime numbers between intervals using functions in C Programming language.
If you have any doubt regarding the problem, feel free to contact us in the comment section. We will be delighted to help you.
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