Java中的 Scanner useDelimiter() 方法及示例

useDelimiter（模式模式）

Java.util.Scanner类的useDelimiter(Pattern pattern)方法将此扫描仪的分隔模式设置为指定的模式。

句法：

public Scanner useDelimiter(Pattern pattern)

参数：该函数接受指定分隔模式的强制参数模式。

返回值：该函数返回此扫描仪。

下面的程序说明了上述函数：

方案一：

Java

// 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.

使用分隔符（字符串模式）

Java.util.Scanner类的useDelimiter(String pattern)方法 将此扫描器的分隔模式设置为从指定 String 构造的模式。

句法：

public Scanner useDelimiter(String pattern)

参数：该函数接受指定分隔模式的强制参数字符串模式。

返回值：该函数返回此扫描仪。

下面的程序说明了上述函数：

方案一：

Java

// 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： https: Java Java.lang.String)