Compound assignment operators in Java are used to perform an operation on a variable and then assign the result back to that variable in a concise way. These operators combine both an arithmetic operation and assignment in a single step. Using compound assignment operators can make your code more readable and shorter.

Here’s a list of the compound assignment operators in Java:

**Addition assignment (**: Adds the right operand to the left operand and assigns the result to the left operand.`+=`

)java`int a = 5;`

`a += 2; // Equivalent to a = a + 2; Now, a is 7.`

**Subtraction assignment (**: Subtracts the right operand from the left operand and assigns the result to the left operand.`-=`

)java`int b = 5;`

`b -= 2; // Equivalent to b = b - 2; Now, b is 3.`

**Multiplication assignment (**: Multiplies the left operand by the right operand and assigns the result to the left operand.`*=`

)java`int c = 3;`

`c *= 2; // Equivalent to c = c * 2; Now, c is 6.`

**Division assignment (**: Divides the left operand by the right operand and assigns the result to the left operand.`/=`

)java`int d = 6;`

`d /= 2; // Equivalent to d = d / 2; Now, d is 3.`

**Modulus assignment (**: Takes the modulus using two operands and assigns the result to the left operand.`%=`

)java`int e = 5;`

`e %= 2; // Equivalent to e = e % 2; Now, e is 1.`

Other compound assignment operators include:

**Bitwise AND assignment (**: Performs a bitwise AND on both operands and assigns the result to the left operand.`&=`

)**Bitwise OR assignment (**: Performs a bitwise OR on both operands and assigns the result to the left operand.`|=`

)**Bitwise XOR assignment (**: Performs a bitwise XOR on both operands and assigns the result to the left operand.`^=`

)**Left shift assignment (**: Shifts the left operand left by the number of bits specified by the right operand and assigns the result to the left operand.`<<=`

)**Right shift assignment (**: Shifts the left operand right by the number of bits specified by the right operand and assigns the result to the left operand.`>>=`

)**Unsigned right shift assignment (**: Shifts the left operand right (unsigned) by the number of bits specified by the right operand and assigns the result to the left operand.`>>>=`

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Using these operators can simplify your code and make it more efficient by reducing the verbosity of common mathematical and bitwise operations.