Java Fundamentals Review II: Operators, keyboard entry, flow control statements, if statements, ternary operations

1. Operators

1.1, arithmetic operator + ( addition has three usages: addition, plus, String connector )-*/% + +--

1.1.1,/is the pickup,% is the surplus

Usage of 1.1.2, + + and--(A: function is self-increment, self-subtraction)

B: used alone: in front and back

C: Participate in operation using:

put in front is to increment or subtract first, then participate in the Operation

int A=10;int b=++a;-----------b=11

In the back is the first to participate in the operation, and then self-increase or reduce

int A=10;int b=a++; ----------b=10

1.2, assignment operator (=,+=,-=,*=,/=,%=) = is the most basic assignment operator int x=10; assigns 10 to X;

Knowledge Points:+=,-=,*=,/=,%= Implicit automatic casts

such as: Short S=1; s=s+1; Error, because the int to short needs a strong turn

Short s1=1;s1+=1;//Auto-strong ( implied ) ===== (short) (s1+1)

1.3. Comparison operator (= = = > < >= <=) The result is a Boolean

1.4. Logical Operators (& |  ^   ! && | | The expression used to concatenate the result is Boolean

int a=10;
int b=20;
int c=30;

Conclusion:& logic and: there is false and false, only true if it is full.

| Logical OR: TRUE if True

^ Logical XOR is the same as false, different true, couple relationship.

! False if not true, true if not false.

&& False is true only if it is true: only it will short-circuit if the previous condition is not satisfied, the latter one will not execute at all

|| Logical OR: There is true if true, except that it will short-circuit if the previous one is true and the latter one will not execute at all.

1.5, bitwise operations (>> << >>> <<<< ^ | &)

^ One data for another data bit XOR or two times, the number does not change as 2^5^5===2

--To be continued

Java Fundamentals Review II: Operators, keyboard entry, flow control statements, if statements, ternary operations