/**
 * This class is used to compute prime numbers and has an semantical error in line 15, since primes are only tested for values below 'bound'.
 * @author christian
 *
 */
public class Prime {    
        /**
         * Counts prime numbers up to a specified bound.
         * @param bound Count up to this number.
         * @return Number of primes.
         */
        public int countPrimesUpTo(int bound){
                int count = 0;
                
                for(int i = 2; i < bound; i++){
                        if (isPrime(i)) count++;
                }
                
                return count;
        }
        
        /**
         * Checks whether an integer is a prime number or not.
         * @param number Number to be checked.
         * @return true if number is prime, false otherwise.
         */
        public boolean isPrime(int number){
                if(number == 1){
                        return false;
                }else if(number == 2){
                        return true;
                }else if(number % 2 == 0){
                        return false;
                }else{
                        for(int i = 2; i < Math.sqrt(number)+1; i += 1){
                                if (number % i == 0) return false;
                        }
                }
                return true;
        }
        
        /**
         * Returns a formatted string of the first prime numbers up to bound. (e.g. '[2, 3, 5, 7]')
         * @param bound Highest number that should be tested.
         * @return String containing prime numbers up to bound.
         */
        public String getStringOfPrimesUpTo(int bound){
                boolean format = false;
                String string = "[";
                
                for(int i = 2; i <= bound; i++){
                        if (this.isPrime(i)){
                                if (format) string += ", ";
                                string += i;
                                format = true;
                        }
                }
                
                return string += "]";
        }
}