The Assignment Operator - Java

The Assignment Operator

You have been using the assignment operator since Chapter 2. Now it is time to take a formal look at it. The assignment operator is the single equal sign, =. The assignment operator works in Java much as it does in any other computer language. It has this general form:

var = expression;

Here, the type of var must be compatible with the type of expression.

The assignment operator does have one interesting attribute that you may not be familiar with: it allows you to create a chain of assignments. For example, consider this fragment:

int x, y, z;

x = y = z = 100; // set x, y, and z to 100

This fragment sets the variables x, y, and z to 100 using a single statement. This works because the = is an operator that yields the value of the right-hand expression. Thus, the value of z = 100 is 100, which is then assigned to y, which in turn is assigned to x. Using a “chain of assignment” is an easy way to set a group of variables to a common value.