The comma operator

The comma operator

Earlier in this chapter I stated that the comma operator (not the comma separator, which is used to separate function arguments) has only one use in Java: in the control expression of a for loop. In both the initialization and step portions of the control expression you can have a number of statements separated by commas, and those statements will be evaluated sequentially. The previous bit of code uses this ability. Here's another example:

Here's the output:

You can see that in both the initialization and step portions the statements are evaluated in sequential order. Also, the initialization portion can have any number of definitions of one type.