Java Scanner useDelimiter()方法及示例

useDelimiter(Pattern pattern)

java.util.Scanner 类的 useDelimiter(Pattern pattern) 方法将该扫描仪的定界模式设置为指定的模式。

语法

public Scanner useDelimiter(Pattern pattern)

参数： 该函数接受一个强制性参数 pattern ，该参数指定了一个定界模式。

返回值： 该函数返回 该Scanner

下面的程序说明了上述函数。

程序1 :

// Java program to illustrate the useDelimiter(Pattern Pattern)
// method of Scanner class in Java
 
import java.util.*;
import java.util.regex.Pattern;
 
public class GFG1 {
    public static void main(String[] argv)
        throws Exception
    {
 
        String s = "Geeksforgeeks has Scanner Class Methods";
 
        // create a new scanner
        // with the specified String Object
        Scanner scanner = new Scanner(s);
 
        // print a line of the scanner
        System.out.println("Scanner String: \n"
                           + scanner.nextLine());
 
        // display the old delimiter
        System.out.println("Old delimiter: "
                           + scanner.delimiter());
 
        // change the delimiter of this scanner
        scanner.useDelimiter(Pattern.compile(".ll."));
 
        // display the new delimiter
        System.out.println("New delimiter: "
                           + scanner.delimiter());
 
        // close the scanner
        scanner.close();
    }
}

输出

Scanner String: 
Geeksforgeeks has Scanner Class Methods
Old delimiter: \p{javaWhitespace}+
New delimiter: .ll.

useDelimiter(String pattern)

java.util.Scanner 类的 useDelimiter(String pattern) 方法将该扫描器的定界模式设置为由指定的字符串构建的模式。

语法

public Scanner useDelimiter(String pattern)

参数： 该函数接受一个强制性参数字符串 pattern ，它指定了一个定界模式。

返回值： 该函数返回 这个扫描器

下面的程序说明了上述函数。

程序1 :

// Java program to illustrate the useDelimter(String Pattern)
// method of Scanner class in Java
 
import java.util.*;
 
public class GFG1 {
    public static void main(String[] argv)
        throws Exception
    {
 
        String s = "Geeksforgeeks has Scanner Class Methods";
 
        // create a new scanner
        // with the specified String Object
        Scanner scanner = new Scanner(s);
 
        // print a line of the scanner
        System.out.println("Scanner String: \n"
                           + scanner.nextLine());
 
        // print the old delimiter
        System.out.println("Old Delimiter: "
                           + scanner.delimiter());
 
        // change the delimiter
        scanner.useDelimiter("Wor");
 
        // print the new delimiter
        System.out.println("New Delimiter: "
                           + scanner.delimiter());
 
        // close the scanner
        scanner.close();
    }
}

输出

Scanner String: 
Geeksforgeeks has Scanner Class Methods
Old Delimiter: \p{javaWhitespace}+
New Delimiter: Wor

参考资料： https://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html#useDelimiter(java.lang.String)