极客教程Java Scanner skip()方法及示例
skip(Pattern pattern)
java.util.Scanner 类的 skip(Pattern pattern) 方法跳过与指定模式相匹配的输入，忽略了分隔符。如果指定模式的锚定匹配成功，该函数将跳过输入。
语法
public Scanner skip(Pattern pattern)
参数： 该函数接受一个强制性参数 pattern ，指定一个字符串作为要跳过的模式。
返回值： 该函数返回这个扫描器。
异常： 该方法会抛出以下异常。
- NoSuchElementException：当指定的模式没有找到时。
- IllegalStateException：当这个扫描器被关闭时。
下面的程序说明了上述函数。
程序1 :
// Java program to illustrate the
// skip() 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 - "
+ "A Computer Science Portal for Geeks";
System.out.println("String trying to get input:\n"
+ s);
// create a new scanner with
// the specified String Object
Scanner scanner = new Scanner(s);
// skip the word that
// matches with the pattern ..eks
System.out.println("Skipping 5 letter words"
+ " that ends with 'eks'\n");
scanner.skip(Pattern.compile("..eks"));
// print a line of the scanner
System.out.println("Input Scanner String: \n"
+ scanner.nextLine());
// close the scanner
scanner.close();
}
}
输出:
String trying to get input:
GeeksForGeeks - A Computer Science Portal for Geeks
Skipping 5 letter words that ends with 'eks'
Input Scanner String:
ForGeeks - A Computer Science Portal for Geeks
程序2： 演示NoSuchElementException
// Java program to illustrate the
// skip() 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
{
try {
String s = "GeeksForGeeks - "
+ "A Computer Science Portal for Geeks";
System.out.println("String trying to get input:\n"
+ s);
// create a new scanner with
// the specified String Object
Scanner scanner = new Scanner(s);
// skip the word that
// matches with the pattern and
System.out.println("Skipping 3 letter words"
+ " and\n");
scanner.skip(Pattern.compile("and"));
// print a line of the scanner
System.out.println("Input Scanner String: \n"
+ scanner.nextLine());
// close the scanner
scanner.close();
}
catch (Exception e) {
System.out.println("Exception thrown: " + e);
}
}
}
输出:
String trying to get input:
GeeksForGeeks - A Computer Science Portal for Geeks
Skipping 3 letter words and
Exception thrown: java.util.NoSuchElementException
程序3： 演示IllegalStateException
// Java program to illustrate the
// skip() 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
{
try {
String s = "GeeksForGeeks - "
+ "A Computer Science Portal for Geeks";
System.out.println("String trying to get input:\n"
+ s);
// create a new scanner with
// the specified String Object
Scanner scanner = new Scanner(s);
// close the scanner
scanner.close();
System.out.println("Scanner Closed");
// skip the word that
// matches with the pattern and
System.out.println("Trying to Skip 3 letter words"
+ " and\n");
scanner.skip(Pattern.compile("and"));
// print a line of the scanner
System.out.println("Input Scanner String: \n"
+ scanner.nextLine());
}
catch (Exception e) {
System.out.println("Exception thrown: " + e);
}
}
}
输出:
String trying to get input:
GeeksForGeeks - A Computer Science Portal for Geeks
Scanner Closed
Trying to Skip 3 letter words and
Exception thrown: java.lang.IllegalStateException: Scanner closed
skip(String pattern)
java.util.Scanner 类的 skip(String pattern) 方法会跳过与由指定字符串构建的模式相匹配的输入。skip(pattern)和 skip(Pattern.compile(pattern))在被调用时的表现完全相同。
语法
public Scanner skip(String pattern)
参数： 该函数接受一个强制性参数字符串 pattern ，它指定了一个表示要跳过的模式的字符串。
返回值： 该函数返回这个扫描器
异常： 当这个扫描仪被关闭时，该方法会抛出IllegalStateException。
下面的程序说明了上述函数。
程序1 :
// Java program to illustrate the
// skip() method of Scanner class in Java
import java.util.*;
public class GFG1 {
public static void main(String[] argv)
throws Exception
{
String s = "GeeksForGeeks - "
+ "A Computer Science Portal for Geeks";
System.out.println("String trying to get input:\n"
+ s);
// create a new scanner with
// the specified String Object
Scanner scanner = new Scanner(s);
// skip the word that
// matches with the pattern ..eks
System.out.println("Skipping 5 letter words"
+ " that ends with 'eks'\n");
scanner.skip("..eks");
// print a line of the scanner
System.out.println("Input Scanner String: \n"
+ scanner.nextLine());
// close the scanner
scanner.close();
}
}
输出:
String trying to get input:
GeeksForGeeks - A Computer Science Portal for Geeks
Skipping 5 letter words that ends with 'eks'
Input Scanner String:
ForGeeks - A Computer Science Portal for Geeks
程序2： 演示IllegalStateException
// Java program to illustrate the
// skip() method of Scanner class in Java
import java.util.*;
public class GFG1 {
public static void main(String[] argv)
throws Exception
{
try {
String s = "GeeksForGeeks - "
+ "A Computer Science Portal for Geeks";
System.out.println("String trying to get input:\n"
+ s);
// create a new scanner with
// the specified String Object
Scanner scanner = new Scanner(s);
// close the scanner
scanner.close();
System.out.println("Scanner Closed");
// skip the word that
// matches with the pattern and
System.out.println("Trying to Skip 3 letter words"
+ " and\n");
scanner.skip("and");
// print a line of the scanner
System.out.println("Input Scanner String: \n"
+ scanner.nextLine());
}
catch (Exception e) {
System.out.println("Exception thrown: " + e);
}
}
}
输出:
String trying to get input:
GeeksForGeeks - A Computer Science Portal for Geeks
Scanner Closed
Trying to Skip 3 letter words and
Exception thrown: java.lang.IllegalStateException: Scanner closed
**参考资料: ** https://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html#skip(java.util.regex.Pattern)