Get month number from month name

Question

I have this.

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    String monthName = br.readLine();

How to get mon

Answer 1

Use Java's Calendar class. It can parse any given string into a valid calendar instance. Here is an example (assuming that the month is in english).

Date date = new SimpleDateFormat("MMMM").parse(monthName);
Calendar cal = Calendar.getInstance();
cal.setTime(date);
println(cal.get(Calendar.MONTH));

You can specify the language in SimpleDateFormat:

String monthName = "März"; // German for march
Date date = new SimpleDateFormat("MMMM", Locale.GERMAN).parse(monthName);
Calendar cal = Calendar.getInstance();
cal.setTime(date);
println(cal.get(Calendar.MONTH));

By default, Java uses the user's local to parse the string.

Keep in mind that a computer starts counting at 0. So, January will be 0. If you want a human readable date, you should format the calendar instance:

SimpleDateFormat inputFormat = new SimpleDateFormat("MMMM");
Calendar cal = Calendar.getInstance();
cal.setTime(inputFormat.parse(monthName));
SimpleDateFormat outputFormat = new SimpleDateFormat("MM"); // 01-12
println(outputFormat.format(cal.getTime()));