What operator is a unary operator which means it works with only one operand?

Operators constitute the basic building block to any programming language. Java too provides many types of operators which can be used according to the need to perform various calculations and functions be it logical, arithmetic, relational, etc. They are classified based on the functionality they provide. Here are a few types:

1. Arithmetic Operators
2. Unary Operators
3. Assignment Operator
4. Relational Operators
5. Logical Operators
6. Ternary Operator
7. Bitwise Operators
8. Shift Operators

Unary Operators in Java

Java unary operators are the types that need only one operand to perform any operation like increment, decrement, negation, etc. It consists of various arithmetic, logical and other operators that operate on a single operand. Let’s look at the various unary operators in detail and see how they operate. 

Operator 1: Unary minus(-)

This operator can be used to convert a positive value to a negative one. 

Syntax: 

-(operand)

Illustration: 

a = -10

Example:

Java

a = -10

a = -10

a = -10

Number = 20
Result = -20

Number = 20
Result = -20

Number = 20
Result = -20

Number = 20
Result = -20

Number = 20
Result = -20

Number = 20
Result = -20

Number = 20
Result = -20

Number = 20
Result = -20

Number = 20
Result = -20

Number = 20
Result = -20

!(operand)

Number = 20
Result = -20

!(operand)

!(operand)

!(operand)

!(operand)

!(operand)

!(operand)

!(operand)

!(operand)

!(operand)

cond = !true;
// cond < false

!(operand)

cond = !true;
// cond < false

cond = !true;
// cond < false

cond = !true;
// cond < false

!(operand)

cond = !true;
// cond < false

!(operand)

cond = !true;
// cond < false

!(operand)

Cond is: true
Var1 = 10
Var2 = 1
Now cond is: false
!(a < b) = true
!(a > b) = false

!(operand)

Cond is: true
Var1 = 10
Var2 = 1
Now cond is: false
!(a < b) = true
!(a > b) = false

!(operand)

cond = !true;
// cond < false

Cond is: true
Var1 = 10
Var2 = 1
Now cond is: false
!(a < b) = true
!(a > b) = false

cond = !true;
// cond < false

Number = 20
Result = -20

Cond is: true
Var1 = 10
Var2 = 1
Now cond is: false
!(a < b) = true
!(a > b) = false

Cond is: true
Var1 = 10
Var2 = 1
Now cond is: false
!(a < b) = true
!(a > b) = false

Output

Number = 20
Result = -20

Operator 2: ‘NOT’ Operator(!)

This is used to convert true to false or vice versa. Basically, it reverses the logical state of an operand.

Syntax: 

!(operand)

Illustration: 

cond = !true;
// cond < false

Example:

Java

num++

a = -10

a = -10

Number = 20
Result = -20

Number = 20
Result = -20

Number = 20
Result = -20

Number = 20
Result = -20

Number = 20
Result = -20

Number = 20
Result = -20

Number = 20
Result = -20

Number = 20
Result = -20

Number = 20
Result = -20

Number = 20
Result = -20

!(operand)

Number = 20
Result = -20

!(operand)

!(operand)

num = 5
num++ = 6

!(operand)

++num

++num

++num

!(operand)

!(operand)

!(operand)

++num

++num

++num

++num

!(operand)

!(operand)

num = 5
++num = 6

!(operand)

cond = !true;
// cond < false

num = 5
++num = 6

num = 5
++num = 6

!(operand)

cond = !true;
// cond < false

num = 5
++num = 6

a = -10

!(operand)

cond = !true;
// cond < false

a = -10

a = -10

!(operand)

num = 5
++num = 6

!(operand)

a = -10

!(operand)

cond = !true;
// cond < false

a = -10

a = -10

!(operand)

cond = !true;
// cond < false

a = -10

a = -10

!(operand)

cond = !true;
// cond < false

a = -10

a = -10

Number = 20
Result = -20

Cond is: true
Var1 = 10
Var2 = 1
Now cond is: false
!(a < b) = true
!(a > b) = false

Cond is: true
Var1 = 10
Var2 = 1
Now cond is: false
!(a < b) = true
!(a > b) = false

Output: 

Cond is: true
Var1 = 10
Var2 = 1
Now cond is: false
!(a < b) = true
!(a > b) = false

Operator 3: Increment(++)

It is used to increment the value of an integer. It can be used in two separate ways: 

3.1: Post-increment operator

When placed after the variable name, the value of the operand is incremented but the previous value is retained temporarily until the execution of this statement and it gets updated before the execution of the next statement. 

Syntax: 

num++

Illustration: 

num = 5
num++ = 6

3.2: Pre-increment operator

When placed before the variable name, the operand’s value is incremented instantly.

Syntax: 

++num

Illustration: 

num = 5
++num = 6

Operator 4: Decrement(–)

It is used to decrement the value of an integer. It can be used in two separate ways: 

4.1: Post-decrement operator

When placed after the variable name, the value of the operand is decremented but the previous values is retained temporarily until the execution of this statement and it gets updated before the execution of the next statement. 

Syntax: 

a = -10

Illustration: 

a = -10

4.2: Pre-decrement operator

When placed before the variable name, the operand’s value is decremented instantly. 

Syntax: 

a = -10

Illustration:

a = -10

Operator 5: Bitwise Complement(~)

This unary operator returns the one’s complement representation of the input value or operand, i.e, with all bits inverted, which means it makes every 0 to 1, and every 1 to 0. 

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