Operators and Expressions in Java

An operator is a syntax notation for a particular language used to complete an action.

– Assignment operator – increment operator – arithmetic operator – relational operator – logical operator

-Bitwise operators

Operator	Java
Add	+
Reducing	-
By	*
Except	/
Take the mold	%

1. Integer and Fractional operations

int n =12; int m = 5;float y = n/m; System.out.println (n/m);//          2system.out.println (n/5.0);//        2.4system.out.println (12.0/m);//       2.4system.out.println (y);//            2.0

Note : The output from the last line is 2.0

2. String connector: +

+: Except as an extra, string s = "Hello," + "Tom";　　　　Only one of the operands on the "+" side is a string (string) type, and the system automatically converts the other operand to a string before connecting.　　　　–int a = 1; –system.out.println ("a=" +a);

String s1= "Tom" +1+2; System.out.println (S1);//output: tom12string s2=1+2+ "Tom"; SYSTEM.OUT.PRINTLN (S2);//output: 3Tom

3. Self-adding decrement operator: + + and--

Increment and decrement of pre-order: first operation and then assignment

Increment and decrement: first assignment and then operation

int i = 1; System.out.println (i);//   1system.out.println (++i);//2system.out.println (i);//   2system.out.println (i++) ;//2system.out.println (i);//   3

4. Relational operators

Operator	Java
Equal	==
Not equal	!=
Greater than	>
Less than	<
Less than or equal	<=
Greater than or equal	>=

The return value is of type Boolean.

5. Logical operators

(1). Produces a Boolean value (2). Applies only to Boolean values

operator	Java
logic with	&&
logical OR	| |
logical non

int I=1,j=2;boolean Flag1 = (i>3) && ((i+j) >5); Boolean flag2 = (i<2) | | ({i+j}<6);

6. Bitwise operators

operator	Java
and	&
or	|
Take counter	~
xor	^
Shift left	<<
Right shift	>>

     Bitwise operation of a variable     int x = 9;     int y = x&8;      System.out.println (y);//into binary, then corresponds to bit phase. 1001&1000=1000. y=8     int x = 9;     System.out.println (x<<1);//move left to the equivalent of multiplying by 2.  9*2=18. 1001<<1=10010=2+16=18.

7. Three Mesh condition operator

Syntax format: X? Y:z X is a Boolean expression that calculates the value of x and, if true, the result of the entire expression is y;

int score = 61; String result = score>=60? " Pass ":" Failed "; SYSTEM.OUT.PRINTLN (result);//Pass

8. Precedence of Operators

1. Operational rules: Operators with high precedence are evaluated before operators with lower precedence, with the same precedencefrom left to rightevaluated. 2. Use of parentheses

Priority level	Operator type	Operator
Highest priority level	Unary operators	[ ]  . () (Method call)
		！ ~ + +--+-NEW () (Forced type conversion)
Higher priority	Arithmetic operators Displacement operator	*  /  %  +  -
		<< >>
Lower priority level	Relational operators Displacement operator logical operators	< <= > > = = =
		& ^ |
		&& | |
		?: (Ternary judgment operator, for example: A>b?) X:Y)
Lowest priority level	Assignment operators	=
		+=  -=  *=  /=  %=

Operators and Expressions in Java