Java Reference
In-Depth Information
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// Fig. 6.7: RollDie.java
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// Roll a six-sided die 6,000,000 times.
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import java.security.SecureRandom;
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public class RollDie
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{
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public static void main(String[] args)
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{
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// randomNumbers object will produce secure random numbers
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SecureRandom randomNumbers = new SecureRandom();
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int frequency1 = 0 ; // count of 1s rolled
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int frequency2 = 0 ; // count of 2s rolled
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int frequency3 = 0 ; // count of 3s rolled
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int frequency4 = 0 ; // count of 4s rolled
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int frequency5 = 0 ; // count of 5s rolled
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int frequency6 = 0 ; // count of 6s rolled
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// tally counts for 6,000,000 rolls of a die
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for ( int roll = 1 ; roll <= 6000000 ; roll++)
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{
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int face = 1 + randomNumbers.nextInt( 6 ); // number from 1 to 6
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// use face value 1-6 to determine which counter to increment
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switch (
face
)
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{
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case 1 :
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++frequency1; // increment the 1s counter
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break ;
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case 2:
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++frequency2; // increment the 2s counter
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break ;
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case 3:
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++frequency3; // increment the 3s counter
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break ;
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case 4:
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++frequency4; // increment the 4s counter
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break ;
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case 5:
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++frequency5; // increment the 5s counter
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break ;
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case 6:
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++frequency6; // increment the 6s counter
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break ;
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}
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}
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System.out.println( "Face\tFrequency" ); // output headers
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System.out.printf( "1\t%d%n2\t%d%n3\t%d%n4\t%d%n5\t%d%n6\t%d%n" ,
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frequency1, frequency2, frequency3, frequency4,
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frequency5, frequency6);
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}
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} // end class RollDie
Fig. 6.7 | Roll a six-sided die 6,000,000 times. (Part 1 of 2.)
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