Java Character isLowSurrogate()方法及示例

java.lang.Character.isLowSurrogate(char ch) 是java中的一个内置方法，它可以确定给定的char值是否是Unicode的低代理代码单元（也称为尾部代理代码单元）。这种值本身并不代表字符，但在UTF-16编码中用于表示补充字符。

语法

public static boolean isLowSurrogate(char ch)

参数： 该函数接受一个强制性参数ch，指定要测试的字符。

返回值： 该函数返回一个布尔值。如果字符值在MIN_LOW_SURROGATE和MAX_LOW_SURROGATE之间，返回值为True，否则为False。

以下程序说明了Character.isLowSurrogate()方法。

程序1 :

// Java program to illustrate the
// Character.isLowSurrogate() method
import java.lang.*;
  
public class gfg {
  
    public static void main(String[] args)
    {
  
        // create 2 char primitives c1, c2
        char c1 = '\udc25', c2 = 'h';
  
        // assign isLowSurrogate results of
        // c1, c2 to boolean primitives bool1, bool2
        boolean bool1 = Character.isLowSurrogate(c1);
        System.out.println("c1 is a Unicode low-surrogate ? " + bool1);
  
        boolean bool2 = Character.isLowSurrogate(c2);
        System.out.println(c2 + " is a Unicode low-surrogate ? " + bool2);
    }
}

输出:

c1 is a Unicode low-surrogate ? true
h is a Unicode low-surrogate ? false

程序2

// Java program to illustrate the
// Character.isLowSurrogate() method
import java.lang.*;
  
public class gfg {
  
    public static void main(String[] args)
    {
  
        // create 2 char primitives c1, c2
        char c1 = '\udc29', c2 = 'x';
  
        // assign isLowSurrogate results of
        // c1, c2 to boolean primitives bool1, bool2
        boolean bool1 = Character.isLowSurrogate(c1);
        System.out.println("c1 is a Unicode low-surrogate ? " + bool1);
  
        boolean bool2 = Character.isLowSurrogate(c2);
        System.out.println(c2 + " is a Unicode low-surrogate ? " + bool2);
    }
}

输出:

c1 is a Unicode low-surrogate ? true
x is a Unicode low-surrogate ? false

**参考资料: **https://docs.oracle.com/javase/7/docs/api/java/lang/Character.html#isLowSurrogate(char)