ITEC 120 2010fall ibarland

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lect04c
if-else-if

• /** Return whether or not the person must register with Selective Service. * @param age The person's age, in entire years. (E.g. 18mos would be 1 entire year). * @param ___ _______________________________________________ * @return whether or not the person must register with Selective Service. */ boolean mustRegisterForDraft_v2( int age, ____ ______ ) { return _ (age >= 18) __ _______ _; } static void testDraft() { System.out.println("" }

  By the way, now we see more clearly, the advantage of making this its own function -- we don't have to update the rules in several places. In fact, we'll need to update our function further, to account for whether the person is a U.S. citizen, or an alien living in the U.S. In fact, ultimately your code should be a direct translation of the actual regulations, which can be fairly detailed.

• AND, OR, NOT; apply to greet() examples with literals; precedence (); WARN: "if (n < 3 && > 7)"; "n == 3 || 4"
• back to mustRegisterForDraft: in one line
• If spare time:
  factoring out the repeated code in test
  Or: precedence of arithmetic;

    /** Return a greeting, selected randomly from a list of several greetings.
     * @return A greeting (randomly selected, not necessarily uniformly).
     */
    static String greet() {
        int choice = randomInt(100);
        // Object120.randomInt(n) returns a number in [0,n) = {0,1,2,...,n-1}.

        String msg;

        if (choice < 30) {
            msg = "Hello.";
        } else if (choice < 33) {  
            msg = "Aloha.";
        }
        else if (choice < 50) {  
            msg = "Buenos dias, amigo/amiga.";
        }
        else if (choice < 99) {  
            msg = "Yo.";
        }
        else if (choice < 100) {  
            // Not an advisable greeting.  Use sparingly.
            msg = "I am a javabot: System dot out dot println open \"hello\" close.";
        }
        else {
            System.err.println( "Uh-oh, I didn't expect to reach here!" );
            msg = "A dummy initialiazation for `msg`, to appease the compiler.";
        }

        return msg;
    }

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©2010, Ian Barland, Radford University Last modified 2010.Sep.29 (Wed)

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