Java中的字符.isIdentifierIgnorable() 和示例

1. Java.lang。 字符.isIdentifierIgnorable(char ch)是Java中的一个内置方法，用于确定指定字符是否应被视为Java标识符或 Unicode 标识符中的可忽略字符。

   在Java标识符或 Unicode 标识符中可以忽略以下 Unicode字符：

   • 非空白的 ISO 控制字符
     1. '\u0000' 到 '\u0008'
     2. '\u000E' 到 '\u001B'
     3. '\u007F' 到 '\u009F'
   • 所有具有 FORMAT 通用类别值的字符

   句法：

   public static boolean isIdentifierIgnorable(char ch)

   参数：参数ch是字符数据类型，指的是要测试的字符。

   返回值：如果字符是可以是Java或 Unicode 标识符的一部分的可忽略控制字符，则此方法返回 true，否则返回 false。

   下面的程序说明了字符.isIdentifierIgnorable(char ch) 方法：

   方案一：

   // Java program to illustrate
   // Character.isIdentifierIgnorable(char ch) method
   import java.lang.*;
     
   public class gfg {
     
      public static void main(String[] args) {
     
         // Creates 2 character primitives c1, c2 and assigning values
         char c1='\u0000', c2= '9';
     
         // Assigns isIdentifierIgnorable results of 
         // c1, c2 to boolean primitives
         boolean  bool1 = Character.isIdentifierIgnorable(c1);
         boolean  bool2 = Character.isIdentifierIgnorable(c2);
     
         String str1 = "c1 is an ignorable control character is " + bool1;
         String str2 = "c2 is an ignorable control character is " + bool2;
     
         System.out.println( str1 );
         System.out.println( str2 );
      }
   }
   

   输出：

   c1 is an ignorable control character is true
   c2 is an ignorable control character is false
   

   方案二：

   import java.lang.*;
     
   public class gfg {
     
      public static void main(String[] args) {
     
         // Create 2 character primitives c1, c2 and assigning values
         char c1='\u000E', c2= '8';
     
         // Assigns isIdentifierIgnorable results of 
         // c1, c2 to boolean primitives
         boolean  bool1 = Character.isIdentifierIgnorable(c1);
         boolean  bool2 = Character.isIdentifierIgnorable(c2);
     
         String str1 = "c1 is an ignorable control character is " + bool1;
         String str2 = "c2 is an ignorable control character is " + bool2;
     
         System.out.println( str1 );
         System.out.println( str2 );
      }
   }
   

   输出：

   c1 is an ignorable control character is true
   c2 is an ignorable control character is false
   

2. Java.lang。 字符.isIdentifierIgnorable(int codePoint)在所有方面都类似于前面的方法。

   句法：

   public static boolean isIdentifierIgnorable(int codePoint)
   

   参数：该函数接受一个整数数据类型的参数 codePoint，它指定要测试的字符（Unicode 代码点）。

   返回值：如果字符是可以是Java或 Unicode 标识符的一部分的可忽略控制字符，则此方法返回 true，否则返回 false。

   下面的程序说明了字符.isIdentifierIgnorable(int codepoint) 方法：
   方案一：

   // Java program to demonstrate 
   // the Character.isIdentifierIgnorable(int codepoint) method
     
   import java.lang.*;
     
   public class gfg {
     
      public static void main(String[] args) {
     
         // Integer primitives c1, c2
         int c1 = 0x019f, c2 = 0x1abc;
     
         // Assign isIdentifierIgnorable results of cp1, cp2
         // to boolean primitives bool1, bool2
        boolean bool1 = Character.isIdentifierIgnorable(c1);
        boolean bool2 = Character.isIdentifierIgnorable(c2);
     
         // Print bool1, bool2 values
         System.out.println( "c1 is an ignorable control character?"+
         " ans is "+bool1);
         System.out.println( "c2 is an ignorable control character?"+
         " ans is "+bool2);
      }
   }
   

   输出：

   c1 is an ignorable control character? ans is false
   c2 is an ignorable control character? ans is false
   

   方案二：

   // Java program to demonstrate 
   // the Character.isIdentifierIgnorable(int codepoint) method
     
   import java.lang.*;
     
   public class gfg {
     
      public static void main(String[] args) {
     
         // Integer primitives c1, c2
         int c1 = 0x119f, c2 = 0x0abc;
     
         // Assign isIdentifierIgnorable results of cp1, cp2
         // to boolean primitives bool1, bool2
        boolean bool1 = Character.isIdentifierIgnorable(c1);
        boolean bool2 = Character.isIdentifierIgnorable(c2);
     
         // Print bool1, bool2 values
         System.out.println( "c1 is an ignorable control character?"+
         " ans is "+bool1);
         System.out.println( "c2 is an ignorable control character?"+
         " ans is "+bool2);
      }
   }
   

   输出：

   c1 is an ignorable control character? ans is false
   c2 is an ignorable control character? ans is false
   

参考： https: Java/lang/ 字符.html#isIdentifierIgnorable(char)