How do I input an array whose length may vary? The input is space delimited and ends when I press enter
public class ArrayInput {
public static void main(String args[]){
ArrayList<Integer> al = new ArrayList<Integer>();
Scanner sc = new Scanner(System.in);
while(){//what condition to use here?
al.add(sc.nextInt());
}
}
}
An example would be:
1 2 5 9 7 4 //press enter here to mark end of input
Read the entire line using sc.nextLine()
and then split()
using \\\\s+
. This way, you don't have to worry about size of input (number of elements). Use Integer.parseInt()
to parse Strings as integers.
Since all your input is in a single line, you can read the entire line and then split it to integers :
String line = sc.nextLine();
String[] tokens = line.split(" ");
int[] numbers = new int[tokens.length];
for (int i=0; i<numbers.length;i++)
numbers[i] = Integer.parseInt(tokens[i]);
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.