Java Scanner nextLong()方法

java.util.Scanner.nextLong(int radix) 方法扫描输入的下一个标记为一个long。此方法将抛出InputMismatchException，如果如下文所述的下一个标记不能转换为有效的long值。如果转换成功，则scanner执行匹配的输入。

1 语法

public long nextLong(int radix)

2 参数

radix：基数用于将标记解释为一个int值

3 返回值

此方法返回从输入信息扫描的long值

4 示例 

package com.yiidian;

/**
 * 一点教程网： http://www.yiidian.com
 */
/**
 * java.util.Scanner.nextLong(int radix)方法的例子
 */
import java.util.*;

public class Demo {

    public static void main(String[] args) {

        String s = "Hello World! 3 + 3.0 = 6.0 true ";
        Long l = 13964599874l;
        s = s + l;

        // create a new scanner with the specified String Object
        Scanner scanner = new Scanner(s);

        // find the next long token and print it
        // loop for the whole scanner
        while (scanner.hasNext()) {

            // if no long is found, print "Not Found:" and the token
            System.out.println("Not Found :" + scanner.next());

            // if the next is a long, print found and the long with radix 20
            if (scanner.hasNextLong()) {
                System.out.println("Found :" + scanner.nextLong(20));
            }

        }

        // close the scanner
        scanner.close();
    }
}

输出结果为：

Not Found :Hello
Not Found :World!
Found :3
Not Found :+
Not Found :3.0
Not Found :=
Not Found :6.0
Not Found :true
Found :12014353515344