Java face question

1. Character Definition:

        Char c=65;        System.out.println (c);

Output Result:

A

Parsing: Defining character patterns in Java:

• Direct definition character: Char c1= ' A ';
• ASCII code corresponding to character: Char c2=65;
• The byte definition range is -128~127

2, program output results

        int a = 5;        System.out.println ("Vlaue is" + ((a < 5)? 10.9:9));

Output Result:

Vlaue is 9.0

Conditional expression Execution Description:

• The expression 1 is solved first, if the value is not 0, the condition is true, the expression 2 is solved, and the value of the expression 2 is the value of the entire conditional expression, and if the value of expression 1 is 0 and the condition is false, then the value of expression 3 is the value of the entire conditional expression.
• Conditional expressions have precedence over the assignment operator only, and are lower than all operators that were previously encountered.
• The binding direction of the conditional operator is "from right to left".
• As long as there are different types in an operation, involving type conversions, the compiler will move down (the basic type ) and then perform the operation.
• The last two expressions in the trinocular operation, one is a constant expression, the other is the T type, and the constant expression can be represented by the T type, then the output is the T type.

Analysis: Because there is a 10.9 in front, so 9 is automatically promoted to 9.0, so the final output is 9.0.

3, program output results

        char x = ' x ';         int i = ten;        System.out.println (false ?) i:x);        System.out.println (false ?) 10:X);

Output Result:

120
X

Analysis: int i=10; I is a variable, so the first output x is promoted to int type, ' X ' corresponds to a value of 120, so output 120; When the last two expressions in the trinocular operation are a constant expression (10 in the subject), the other is the T type (char in the case), and the constant expression can be represented by the T type, the output is the T type. Because 10 is a constant and can be represented as a char type, the output is char.

4. The following output results:

 Public class test1 {    privateint  count;      Public Static void Main (string[] args) {        //  TODO auto-generated method stub           New test1 (in);        System.out.println (T1.count);    }    Test1 (int  ballcount) {        = ballcount;    }}

Output Result:

99

Analysis: Count is defined as a private property and does not prevent the constructor from initializing it, but it is also possible to invoke a private property in the class, but not if it is not in the same class.

 Public class test1 {    publicstaticvoid  main (string[] args) {        new Test2 (n);        System.out.println (T2.count);    }} class test2 {    privateint  count2;    Test2 (int  ballcount) {        = ballcount;    }}

The code above compiles an error: The field Test2.count2 is not visible

Java face question