[XtraJava] - CompletionDays

CompletionDays.java

// Display number of days ahead/behind scheduled readings

class ReadCalc {
    int days;
    int pgs_per_day;
    int current_days;
    
    ReadCalc(int days, int pgs_per_day, int current_days) {
        this.days = days;
        this.pgs_per_day = pgs_per_day;
        this.current_days = current_days;
    }
    
    double calc_total_pgs() {
        return (double) days * pgs_per_day;
    }
    
    double calc_ahead_behind() {
        return (double) current_days - (days * pgs_per_day);
    }
    
    boolean ahead() {
        if(calc_ahead_behind() > 0) return true;
        else return false;
    }
}

class CompletionDays {
    public static void main(String args[]) {
        int total_days, pgs_per_day, current_pg;
        double total_pgs, result;
        boolean ahead;
        
        total_days = 57;
        pgs_per_day = 2;
        current_pg = 134;
        
        ReadCalc dc = new ReadCalc(total_days, pgs_per_day, current_pg);
        
        total_pgs = dc.calc_total_pgs();
        result = dc.calc_ahead_behind();
        ahead = dc.ahead();
        
        System.out.println("You should have read " + total_pgs + 
                           " pages in " + total_days + " days.");
        
        if(ahead) System.out.println("You are ahead " + result + " pgs.");
        else {
            result *= -1;
            System.out.println("You are behind " + result + " pgs.");
        }
    }
}