 ### Program 23:To Print all prime number within the given number

Program 23:

```#include<stdio.h>
main()
{
int num,i,count=0,j;
printf("Enter a number \n");
scanf("%d",&num);
printf("The Prime numbers upto %d are\n",num);
for(i=1;i<=num;i++)
{
count=0;
for(j=1;j<=i;j++)
{
if(i%j==0)
{
count++;
}
}
if(count==2)
{
printf("%d\n",i);
}
}
}```
Explanation:
1. The Program starts with initializing
• num → For storing the number to get all prime numbers between 1 and num
• i,jtemporary variables
• count → To count the number of divisors
2. ```printf("Enter a number \n");
scanf("%d",&num);```
To take value from user.Let us assume it be 8(num=8)
3. The loop iterates from i=1 to 8 one by one.Then count is made zero for every iteration.
4. Now j will iterate from 1 to i and checks if any prime number is there between 1 and i. For example: if it is 5th iteration then i =5
• Iteration 1: Then the for loop j starts as j=1,jtrue then loop continues
• if i%j → 5%1==0 which is true,
• then count=1
• Iteration 2: Then the for loop j starts as j=2,jtrue then loop continues
• if i%j → 5%2==0 which is false,
• then count remains same i.e. count=1;
• Iteration 3: Then the for loop j starts as j=3,jtrue then loop continues
• if i%j → 5%3==0 which is false,
• then count remains same i.e. count=1;
• Iteration 4: Then the for loop j starts as j=4,jtrue then loop continues
• if i%j → 5%4==0 which is false,
• then count remains same i.e. count=1;
• Iteration 5: Then the for loop j starts as j=5,jtrue then loop continues
• if i%j → 5%5==0 which is true,
• then count=2
• Iteration 6: Then the for loop j starts as j=6,jfalse then loop terminates
• Now if count==2 → true then this will be the prime number so this number is printed i.e i=5 is printed.
5. Like the above iteration it checks each and every value of i whether it is prime or not and if it is prime it will print else not.
Output:

#### 1 comment:

1. Hey! you did such a nice work Check out prime number program in c

 Donate Buy me a coffee \$2.00 USD Buy me a burger \$5.00 USD Buy me a pizza \$10.00 USD Compiler Used by me C-Free 5.0(Recommended) Other Compilers Code Blocks(Recommended) Online Compilers Ideone(Remember to give input before executing online where ever necessary)