Java arithmetic operations

Operator arithmetic operators:

Addition (+) subtraction (-) multiplication (*) Division (/) modulus (%)

Addition:

String type: concatenation of strings.

Division:

1.0/0 Display Infinity Infinity

0.0/0.0 Show Nan:not A number is not a numeric value

0.0/0.0 = = 0.0/0.0 in Java itself is not equal to its own condition result is false

The modulo is also called the surplus

Self-increment/decrement:

Self-increment decrement can only be used for variables: operators have precedence over other operators.

Operation rules:

1. The self-increment is counted for the variable itself (i++ ++i)

The value of the variable is increased from 1

2. Assign a value to another variable using the result of a variable and an expression of the self-increment operator

A The increment operator is on the right: the result of the expression is the original value of the variable, as the result of the expression. The variable will still be self-increasing

Two The increment operator is on the left: the result of the expression is the value of the variable's original value since the increment, as the result of the expression. The variable will still be self-increasing

3. Assign a variable to the variable itself using the result of an expression of the increment operator

y=y++: The result of the expression is cached, then self-increment, and finally the result of the expression is assigned to Y

Y=++y: The result of the expression is the increment of the original value of the variable, and finally the result of the expression is assigned to Y

Assignment operators:

The operation symbols are: = + = = *=/=%=

Assign value from right to left

There is an implicit conversion, such as I *= 2.0 can only be seen as I = i * 2.0 The actual result is a defined int type

Comparison operators

Symbols: = = = = > < >= <= instanceof ( Type comparison operator, only for reference type data comparisons)

Attention:

1. The result type of the comparison operator expression is Boolean
2. = = = > < >= <= is a two-tuple operator with only two operands
3. Instanceof is to determine whether an object belongs to a certain kind of type

instanceof Rules of Operation:

Value variable or expression to be instanceof type

logical operators

& (And) | (or) &&(dual vs. logic) | |   (dual or logical OR) ^ different or ! Non -

Rules for logical operators:

&: Both sides are true and the result is true

|: As long as one side is true, the result is true

&&: Both sides are true and the result is true

| |: As long as one side is true, the result is true

^: Different sides, the result is true, otherwise false

！ : Logical Non-

1. Both parameters and the data type of the operation are of type Boolean

2. The result type of the logical operator expression is Boolean

The role of logical operators:

Is the combination judgment applied to multiple conditions.

&& | | and the difference between & |:

& | can either act as a logical operation, or it can be a bitwise operator

Determines whether the result of an expression is a Boolean type

&& | | There is a short-circuit behavior:

&&: When the current face is false, the result of the entire expression is false and the expression after it is no longer operational

|| : When the current face is true, the expression after the whole expression is true is not an operation

Bit operations (understanding)

Concept: Binary is an operation that sees 1 as true and 0 as false.

Trinocular Operations: Syntax:

A? B:c

A: A Boolean-type expression

The result types of B and C are generally the same

Rules

According to the result of a: if true, the result of the whole trinocular operator expression is the result of the B-expression

If False, the result of the expression of the entire Trinocular operator is the result of the C-expression

Attention:

The trinocular operator requires a variable to receive

Java arithmetic operations