The "JAVA" operator and the logical operator

1. Arithmetic operators

+: addition (+ + Plus)

-: Subtraction (---self-subtraction)

*: Multiplication

/: Division

%: Take the remainder operation

2. Relational operators

<: You can only compare relationships between basic types of data, and you cannot compare relationships between objects.

>: (Same relational operator "<")

<=: (Same relational operator "<")

>=: (Same relational operator "<")

= =: If you use this operator to compare references (variables) of two objects, you are essentially comparing two variables that refer to the same object. The so-called same object refers to whether it is an object stored in the same memory unit that was opened up in the stack (heap).

! =: (same relational operator "= =")

3, the logical operator (the operator can only be a Boolean type)

& Adnd (with) False&true = = False

&& (short circuit) False&&true = = False

| or (or) False|true = = True

|| OR (Short circuit) false| | True = = True

! Not (non)!true = = False

^ xor (xor) True^false = = True

Attention:

Logical operators are used to concatenate Boolean expressions. In Java different from the logical expression of mathematics 3<x<5, Java should be written in X>3 & X<5

• The difference between "&" and "&&":

Single "&", on the left, whether true or false, on the right.

Double "&", left false, no calculation on the right.

• "|" And the difference between "| |":
  

Single "|", on the left whether true or false, on the right side are calculated.

Two "|", the Left is true, the right side is not calculated.

• "|" and "&" do bit operations:
  

Binary for | bit operation, only 0|0 time is 0, the other is 1, such as 6|5 first to convert 6 and 5 into binary. 6 binary for 110,5 binary is 101 then the bitwise operation 0|0 0 to have 1 1, calculated as 111,111 for the decimal 7, all 6|5 equals 7

Binary for the & bit operation, only 1&1 1, the other 0, the same can be 6&5 calculate the binary 100,100 into decimal 4

• "^" XOR operation and "~" Inverse Code:
  

Any of the same binary XOR operations are 0,1^1=0,0^0=0, and different XOR operations are 1,1^0=1,0^1=1. The same as 6^5 011 then 011 of the decimal is 3. Prompts for a number XOR or two times to change back itself. Like 6^5^5 's 110,101,101. First get 011, then get 110 all back to the original value, this technique can be used to convert the value, do not need a 3rd variable can be two variable value of each other.

Anti-code: binary for the inverse code calculation. 1 becomes 0, 0 becomes 1. For example, the binary of the sub-~6,6 is 110 on the machine to make up 32 bits before 110 complement 0. Then the anti-code is 111 ..... 001, at this time the inverse code minus 1 to 111 ... 111000, then the original inverse code minus the subtracted code gets 0000 .... 000111 at this time the decimal is-7 then add the original minus 1 to get -7+1 is.

5. Shift operators (integer operators only)

Char, Byte, short type, before the shift, will be converted to type int, the result of the shift is also the int type; the operand to the right of the shift symbol intercepts only the last 5 bits of the second binary (the purpose is to prevent the shift operation from exceeding the int type's representation range: 2 5 is 32, The maximum range of type int is 32-bit), the long type is shifted, the result is still long, and the operator to the right of the shift symbol intercepts only the second binary of the latter 6 bits.

<<: Move Left

>>: Move right, insert 0 at highest bit if sign bit is positive, insert 1 at highest bit if sign bit is negative

>>>: Unsigned Right shift, no matter plus or minus, is inserted at the highest bit 0

Example of Shift:

public class Demo {public static void main (string[] args) {//0000 0000 0000 0101//0000 0000 0000 001 0 System.out.println (5>>1);//2//0000 0000 0000 +//0000 0000 0000 0100 System.out. println (8>>1);//4 System.out.println (3+5>>1);//4 System.out.println (5>>1);//5}}

The "JAVA" operator and the logical operator