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====== Εντολές ελέγχου ροής προγράμματος ====== ===== if - else if - else statement ===== Ανάλογα με την γλώσσα C. Δείτε το παρακάτω παράδειγμα. <code java IfElseDemo.java> class IfElseDemo { public static void main(String[] args) { int testscore = 76; char grade; if (testscore >= 90) { grade = 'A'; } else if (testscore >= 80) { grade = 'B'; } else if (testscore >= 70) { grade = 'C'; } else if (testscore >= 60) { grade = 'D'; } else { grade = 'F'; } System.out.println("Grade = " + grade); } } </code> ===== Switch statement ===== Σε αναλογία με την γλώσσα C, η Java υποστηρίζει την εντολή //switch//. Η ιδιαιτερότητα της //switch// στην Java είναι ότι υποστηρίζει ακεραίους, //enumerated types// ή αλφαριθμητικά. Δείτε τα παρακάτω παραδείγματα με χρήση ακεραίων και αλφαριμθητικών. <code java SwitchDemo.java> public class SwitchDemo { public static void main(String[] args) { int month = 8; String monthString; switch (month) { case 1: monthString = "January"; break; case 2: monthString = "February"; break; case 3: monthString = "March"; break; case 4: monthString = "April"; break; case 5: monthString = "May"; break; case 6: monthString = "June"; break; case 7: monthString = "July"; break; case 8: monthString = "August"; break; case 9: monthString = "September"; break; case 10: monthString = "October"; break; case 11: monthString = "November"; break; case 12: monthString = "December"; break; default: monthString = "Invalid month"; break; } System.out.println(monthString); } } </code> <code java StringSwitchDemo.java> public class StringSwitchDemo { public static int getMonthNumber(String month) { int monthNumber = 0; if (month == null) { return monthNumber; } switch (month.toLowerCase()) { case "january": monthNumber = 1; break; case "february": monthNumber = 2; break; case "march": monthNumber = 3; break; case "april": monthNumber = 4; break; case "may": monthNumber = 5; break; case "june": monthNumber = 6; break; case "july": monthNumber = 7; break; case "august": monthNumber = 8; break; case "september": monthNumber = 9; break; case "october": monthNumber = 10; break; case "november": monthNumber = 11; break; case "december": monthNumber = 12; break; default: monthNumber = 0; break; } return monthNumber; } public static void main(String[] args) { String month = "August"; int returnedMonthNumber = StringSwitchDemo.getMonthNumber(month); if (returnedMonthNumber == 0) { System.out.println("Invalid month"); } else { System.out.println(returnedMonthNumber); } } } </code> | Προηγούμενο: [[:java:control_flow | Ροή Προγράμματος ]] | [[:toc | Περιεχόμενα ]] | Επόμενο: [[:java:loop_statements | Εντολές επανάληψης ]] |
