如何从输入中删除空格？

Question

This is the input: enter image description here

I want to get the last number but how? (1,2,6)

I tried this:

String line = scanner.nextLine();

String[] parts = line.split(" ");

int ProductCount =Integer.parseInt(parts[3].replaceAll(" ", ""));

Answer 1

If you want the last number you can do it like this.

• .*? reluctantly grab the characters
• (\\d+)$ - capture one or more digits at end of string.
• $1 back reference to captured value (21 in this case)
• and convert to an int.

String s = "kssk sk k22 s 21";
int v = Integer.parseInt(s.replaceAll(".*?(\\d+)$","$1"));
System.out.println(v);

prints

21

A somewhat better alternative might be to do the following if there is always a space before the last number.

• get the last index of a white space
• and starting with the next character, get the substring and convert to an integer.

int i = s.lastIndexOf(' '); // returns -1 if no space is found.
int v = Integer.parseInt(s.substring(i+1));