Java basics: Java Operators

Tip: if you have enough energy, remember the operator priority!

1. Arithmetic Operators
+-*/% (Remainder/modulo operator) + + --
 
++ -- A little troublesome. There is a good way to do this: Write a demo and test it yourself!
 
2. Relational operators
> <=! ==<=
 
3. logical operators
& | ^! & |
 
<1> & | ^ operations can be performed on logical expressions or general data types.
 Int A = 1; // 0x0001 <br/> int B = 2; // 0x0002 <br/> system. out. println ("operate on general data types"); <br/> system. out. println (A & B); // 0, calculate the remainder by bit <br/> system. out. println (a ^ B); // 3, by bit or <br/> system. out. println (A | B); // 3, bitwise OR </P> <p> system. out. println ("operations during logical expression"); <br/> system. out. println (A = 1 & B = 2); // true <br/> system. out. println (A = 1 | B = 2); // true <br/>/* true only when the two are inconsistent */<br/> system. out. println (A = 1 ^ B = 2); // true + true = false <br/> system. out. println (A = 12 ^ B = 2); // false + true = true <br/>/false + true = true <br/> system. out. println (A = 1 ^ B = 22); <br/> // true + true = false <br/> system. out. println (A = 12 ^ B = 22); <br/>

<2> & |! Operations can be performed only when logical expressions are performed, and general data types cannot be operated.
// An error is returned. <br/> system. out. println (A & B); <br/> system. out. println (A | B); <br/> system. out. println (! A); <br/>

<3> Differences

&: Common and &: Short Circuit and |: common or |: short circuit or

@ 1. When a is false under the (A & B) condition, the expression is already false;

@ 2. When a is true under the (A | B) condition, no need to judge B. The expression is already true;

@ 3. And & and | both sides must be judged!

4. bitwise operators
& | ^ ~ >><>>>
 
& | ^ ~ Bitwise AND, Or, XOR or, or inversion
> Shifted right: the value of the first digit is 1, and the value of the N digit is shifted right. The value of the N digit is 1 on the left, and the value of the N digit is 0 on the left.
>>> Shifts the unsigned bit to the right. No matter whether the high position is 1 or 0, the value is 0 on the left.
<Shifted left, 0 on the right
 
5. Value assignment operator
=
 
6. Extended operators, I .e. composite Operators
+ =-= * =/= % = And so on
 
 Int A = 7; <br/> // error: Precision may be lost, because int will be automatically converted to float and then calculated with <br/> // 2.6, however, if the result is float and cannot be automatically converted to int, an error is returned. <br/> A = a + 2.6 <br/> // The composite operator is used, it is equivalent to forced conversion <br/> A + = 2.6; <=> A = (INT) (a + 2.6 ); = 9 // forced conversion will result in loss of precision --> saving the decimal point <br/> therefore, A + = 2.6; // not equivalent to a = a + 2.6 <br/>

7. String Connector
+
 
When the system. Out. println statement is used for printing, the tostring () method is called by default. Therefore, as long as either of the string connectors + the operands on both sides is a string,
The system automatically converts another operand to a string and then prints the output.
 

 Int A = 1; <br/> int B = 2; <br/> system. out. println ("A + B =" + A + B); // a + B = 12 <br/> system. out. println ("A + B =" + (A + B); // a + B = 3, parentheses priority <br/> // maximum level, therefore, first calculate the value of A + B and then convert it to string output. <Br/> and so on. </P> <p> system. out. println ("----------------------------"); </P> <p> int I = 12; <br/> char CH = 24; <br/> system. out. println ("I + CH =" + I + CH); // I + CH = 12 characters <br/> // character (24 characters) <br/> system. out. println ("I + CH =" + (I + CH); // I + CH = 36