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javaeclipseif-statementoperatorsshort

Short if-statement "inside" short if-statement

This is my task, and I'm trying to do that with the short if-statements only, the only error I get is that with the syntax where there's "(0.5<=ratio<2)", other than that, Is the construction right? enter image description here

    Scanner scn = new Scanner(System.in);
    int years,kg,cm,MenuA,MenuB,MenuC,A,B,C;
    String not;
    double ratio = cm/kg;
    System.out.println("Please enter your age (years), weight(kg) and height(cm) in that order with spaces");
    years = scn.nextInt();
    kg = scn.nextInt();
    cm = scn.nextInt();

    MenuA = (20<years<<11||40<<years<21)&&(0.5<=ratio<2)?A:MenuB;
    MenuB = (20<years<<11)&&(2<=ratio<<3.5)?B:MenuC;
    MenuC = (40<<years<21)&&(2<=ratio<<3.5)?C:not;

}

}

Solution 
  • 20 < years < 11

    That's not valid Java code. No matter which of the operands you evaluate first, the result will be of type boolean which does not compare to int.

    You'll need to do it the long way:

    20 < years && years < 11

    Or create a method for this:

    betweenExclude(20, years, 11);

    with

    boolean betweenExclude(int a, int b, int c) {
   return a < b && b < c;
}

    and maybe also

    boolean betweenIncludeLeft(double left, double number, double right) {
  return left <= number && number < right;
}

    In terms of readability / maintainability you should also consider writing this in a way, that is easily translated into your table:

    enum Age {
  ELEVEN_TO_TWENTY,
  TWENTYONE_TO_FORTY
};

Age age; 
if(between(11, years, 20)) {
   age = Age.ELEVEN_TO_TWENTY;
}
if(between(21, years, 40)) {
   age = Age.TWENTYONE_TO_FORTY;
}

    Similar for the weight to height ratio

    And later

    if(age.euqals(Age.TWENTYONE_TO_FORTY) && weightratio.equals(WeightRatio.LOW)) {
   //A 
}

    Comment

    Your age-check should include both your boundaries. 11 and 20 have to be in, otherwise people of age 10 and 11 will drop out.