Use of += Addition Assignment Operator in Java

By Sai Venkat Kodithyala

In this tutorial, we are learning how to use and what operations can be done with += operator in Java. In a programming language, x+=y is the same as using x=x+y. += operator is called a compound assignment operator. Compound assignment operators are shortcuts that do a math operation and assignment in a single step.

We can use += operator to increment variables and concatenate strings.

Using += operator to increment values in Java

Let’s see how we can use the += operator in incrementing values.

int a=20;
a+=10;
System.out.println(a);

I have initialized a variable ‘a’ with the value ’20’ which is an Integer type, then with the help of the += operator I have incremented it by ’10’.So the output is:

30

Using += operator to concatenate strings

Let’s see how we concatenate using the += operator.

String b="Hello";
b+="World";
System.out.println(b);

I have initialized a String with the name ‘b’ and assigned value as ‘Hello’, then I have concatenated it ‘World’ using the += operator. So the output looks like this:

HelloWorld

The following is the list of all possible compound assignment operators in Java.

• +=
• -=
• *=
• /=
• %=

Similarly, for the bitwise operator, we have the compound assignment

• &=
• |=
• ^=

Also read: Minimum delete operations to make all elements of array same in Java