使用正则表达式在字符串之间添加空格

Question

I am learning regular expression,hence asking this question. I have a string

String time=7AM-9PM;

I need to add spaces so that the string would come out like this

time=7 AM - 9 PM.

I have tried so far the following regular expression

time.replaceAll("(\\d{1})", "$1 ");

and it is giving output

9 AM-7 PM

Now I just need the space before and after -. Can someone suggest what else I need to add in the regex to achieve the final output.

Thank You

Answer 1

If you tried 7AM-10PM you'd find that 10 would be split up like 1 0 : presumably not what you want!

I managed to do it with 2 replaceAlls:

String time = "7AM-10PM"
System.out.println(time
  .replaceAll("([0-9]+)", "$1 ")   //spaces around numbers
  .replaceAll("([\\-])", " $1 ")); //spaces around '-'

result : 7 AM - 10 PM