while loops and prime numbers

hey guys, i am having trouble with a program that is supposed to keep generating a random number from 1 to 100 until it is prime. if its not then it will use a counter for the numbers that are not prime.

this is what I have so far, i just can't figure out what to put for the beginning next to the while and the if without it bugging.

any suggestions are helpful, thank you.

nInteger = 0;
random = randi(100);
while 
    if 
        nInteger = nInteger + 1;
    end 
end         

[Dyuman Joshi]

What is the purpose of the variable 'nInteger'? Is it to denote a prime number has been found?

Answer 1

[Matt J]

Can't you use isprime()?

isprime(7)

ans = logical
   1

isprime(4)

ans = logical
   0

Answer 2

[John D'Errico]

First, create a list of all the primes that are less than 100. Save them. You can use either the function primes to do this, or just use a fast sieve to do that job.

Now generate random integers between 1 and 100. Test to see if they are in the list of primes. Stop when you find a prime.

Done.