Java Operators
Java Operators
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:
Example
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
- Assignment operators
- Comparison operators
- Logical operators
- Bitwise operators
Arithmetic Operators
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 » |
Here is an example using different arithmetic operators in one example:
Example
int x = 10;
int y = 3;
System.out.println(x + y); // 13
System.out.println(x - y); // 7
System.out.println(x * y); // 30
System.out.println(x / y); // 3
System.out.println(x % y); // 1
int z = 5;
++z;
System.out.println(z); // 6
--z;
System.out.println(z); // 5
Note: When dividing two integers in Java, the result will also be an integer.
For example, 10 / 3 gives 3.
If you want a decimal result, use double values, like 10.0 / 3.
Example
int a = 10;
int b = 3;
System.out.println(a / b); // Integer division, result is 3
double c = 10.0d;
double d = 3.0d;
System.out.println(c / d); // Decimal division, result is 3.333...
Java Assignment Operators
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 » |
Note: Most assignment operators are just shorter ways of writing code.
For example, x += 5 is the same as x = x + 5, but shorter and often easier to read.
Java Comparison Operators
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:
Example
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 » |
Comparison operators are often used in real-world conditions, such as checking if a person is old enough to vote:
Example
int age = 18;
System.out.println(age >= 18); // true, old enough to vote
System.out.println(age < 18); // false, not old enough
Java Logical Operators
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 » |
The example below shows how logical operators can be used in a real situation, like login checks:
Example
boolean isLoggedIn = true;
boolean isAdmin = false;
System.out.println("Regular user: " + (isLoggedIn && !isAdmin));
System.out.println("Has access: " + (isLoggedIn || isAdmin));
System.out.println("Not logged in: " + (!isLoggedIn));
Result:
Is regular user: true
Has any access: true
Not logged in: false
Video: Java Operators
