Checking if the input starts with a number and ends with an Upper letter

Question

I don't know why this isn't working cause the value of they is still 0 even if I type a sentence that starts with a number, contains "end", and ends with an Upper case letter. Also, this should be case sensitive.

if (sentence.startsWith("[0-9]") && sentence.contains("end") && (sentence.endsWith("[A-Z]"))) {
    y++;
}
System.out.println(y);

Answer 1

Your code didn't work because String::startWith doesn't take a regex as a parameter while you are using a regex. You need to use String::matches as shown below:

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int no = 0;
        while (no < 4) {
            System.out.print("Type a number >4: ");
            no = Integer.parseInt(scan.nextLine());
        }
        String sentence;
        int y = 0;
        for (int i = 0; i < no; i++) {
            System.out.print("Enter a sentence: ");
            sentence = scan.nextLine();
            if (sentence.matches("[0-9]+.*end.*[\\p{javaUpperCase}]")) {
                y++;
            }
        }
        System.out.println(y);
    }
}

A sample run:

Type a number >4: 5
Enter a sentence: Hello world
Enter a sentence: 123 Hello World ends with LD
Enter a sentence: 123HelloendHH
Enter a sentence: Good morning
Enter a sentence: 123Good morning
2