Operators are used to perform operations on variables and values.
In the example below, we use the +
operator to add together two values:
Although the +
operator is often used to add together two values, like in the example above, it can also be used to add together a variable and a value, or a variable and another variable:
int sum1 = 100 + 50; // 150 (100 + 50)
int sum2 = sum1 + 250; // 400 (150 + 250)
int sum3 = sum2 + sum2; // 800 (400 + 400)
Java divides the operators into the following groups:
Arithmetic operators are used to perform common mathematical operations.
Operator | Name | Description | Example | Try it |
---|---|---|---|---|
+ | Addition | Adds together two values | x + y | Try it » |
- | Subtraction | Subtracts one value from another | x - y | Try it » |
* | Multiplication | Multiplies two values | x * y | Try it » |
/ | Division | Divides one value by another | x / y | Try it » |
% | Modulus | Returns the division remainder | x % y | Try it » |
++ | Increment | Increases the value of a variable by 1 | ++x | Try it » |
-- | Decrement | Decreases the value of a variable by 1 | --x | Try it » |
Assignment operators are used to assign values to variables.
In the example below, we use the assignment operator (=
) to assign the value 10 to a variable called x:
The addition assignment operator (+=
) adds a value to a variable:
A list of all assignment operators:
Operator | Example | Same As | Try it |
---|---|---|---|
= | x = 5 | x = 5 | Try it » |
+= | x += 3 | x = x + 3 | Try it » |
-= | x -= 3 | x = x - 3 | Try it » |
*= | x *= 3 | x = x * 3 | Try it » |
/= | x /= 3 | x = x / 3 | Try it » |
%= | x %= 3 | x = x % 3 | Try it » |
&= | x &= 3 | x = x & 3 | Try it » |
|= | x |= 3 | x = x | 3 | Try it » |
^= | x ^= 3 | x = x ^ 3 | Try it » |
>>= | x >>= 3 | x = x >> 3 | Try it » |
<<= | x <<= 3 | x = x << 3 | Try it » |
Comparison operators are used to compare two values (or variables). This is important in programming, because it helps us to find answers and make decisions.
The return value of a comparison is either true
or false
. These values are known as Boolean values, and you will learn more about them in the Booleans and If..Else chapter.
In the following example, we use the greater than operator (>
) to find out if 5 is greater than 3:
int x = 5;
int y = 3;
System.out.println(x > y); // returns true, because 5 is higher than 3
Operator | Name | Example | Try it |
---|---|---|---|
== | Equal to | x == y | Try it » |
!= | Not equal | x != y | Try it » |
> | Greater than | x > y | Try it » |
< | Less than | x < y | Try it » |
>= | Greater than or equal to | x >= y | Try it » |
<= | Less than or equal to | x <= y | Try it » |
You can also test for true
or false
values with logical operators.
Logical operators are used to determine the logic between variables or values:
Operator | Name | Description | Example | Try it |
---|---|---|---|---|
&& | Logical and | Returns true if both statements are true | x < 5 && x < 10 | Try it » |
|| | Logical or | Returns true if one of the statements is true | x < 5 || x < 4 | Try it » |
! | Logical not | Reverse the result, returns false if the result is true | !(x < 5 && x < 10) | Try it » |
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