处理不同的字符串日期格式

Question

In java, I have a string with a date in dd-mm-yyyy format:

String value = "31-01-1989";

Now, I want the value in another variable to be ddmmyyyy format:

String value = "31011989";

How to do this?

Answer 1

In this case you can simply remove dashes

value = value.replace("-", "");

or

value = value.replaceAll("-", "");

but according to my tests the first version is a little bit faster. So I personally prefer to use replaceAll only when the first parameter is a regex.

Note that, despite a confusion in the names, String.replace replaces ALL substrings that match the first arg, just as String.replaceAll does. The main difference is that the String.replace treats the first arg as a string literal and String.replaceAll uses it as a regex.

Answer 2

easy solution:

String value1 = "31-01-1989";
String value2 = value1.replace("-", "");

Answer 3

Have a look at SimpleDateFormat for a general solution. Write a SimpleDateFormat to parse the first date and use format in another to have the expected output.

Answer 4

You can use String.replace(Charseq, Charseq) to remove the delimiters.

String value = "31-01-1989";
String value2 = value.replace("-", "");
System.out.println(value2);