关于字符串连接操作符（三）(源自IBM蓝色之路一道笔试题目)

再看下下面的例子

public class TestChar1 {   
    public static void main(String[] args) {  
// int类型的常量可以赋值给任意类型的变量
        byte b = (int) 1;   //OK
        short s = (int) 1;  //OK 
        int i = (int) 1;    //OK
        long l = (int) 1;   //OK
        float f = (int) 1;  //OK 
        double d = (int) 1; //OK  
        char c = (int) 1;   //OK
    }   
} 

public class TestChar2 {   
    public static void main(String[] args) {  
// int类型的变量只能赋值给高类型的变量，不能赋值给低类型的变量（会损失精度）        
         int a = 1;
         char c = (int) a; 
             // Type mismatch: cannot convert from int to char       
         byte b = (int) a; 
             // Type mismatch: cannot convert from int to char
         short s = (int) a;   
             // Type mismatch: cannot convert from int to char
        int i = (int) a;   //OK
        long l = (int) a;  //OK 
        float f = (int) a; //OK  
        double d = (int) a;//OK   
           
    }   
}

public class TestChar3 {   
  
    public static void main(String [] args) {   
  
        int i = 1;   
               // Type mismatch: cannot convert from int to char
        char c = i;   
        System.out.println(c);   
    }   
} 

public class TestChar4 {   
  
    public static void main(String [] args) {   
  
        char c = (int)1; //Ok, 等价于： char c='\001';  
        char d = '\001'; //OK
        System.out.println(c==d); //output: true    }   
}