This is just a quick tip for everyone who often has to work with multi dimensional arrays in Java 8 (or newer).
In this case you might often end with code similar to this:
float[][] values = ...
for (int i = 0; i < values.length; i++) {
for (int k = 0; k < values[i].length; k++) {
float value = values[i][k];
// do something with i, k and value
}
}
If you are lucky you can replace the loops with for-each loops. However, often the indices are required for computations inside the loop.
In such a case you can come up with a simple utility method that looks like this:
private void loop(float[][] values, BiConsumer<Integer, Integer> consumer) {
for (int i = 0; i < values.length; i++) {
for (int k = 0; k < values[i].length; k++) {
consumer.accept(i, k);
}
}
}
We can now loop over array indices like this:
float[][] values = ...
loop(values, (i, k) -> {
float value = values[i][k];
// do something with i, k and value
});
This way you can keep the looping code out of your main logic.
Of course you should change the shown loop() method so it fits your personal needs.
| Reference: | Simplifying nested loops with Java 8 Lambdas from our JCG partner Michael Scharhag at the mscharhag, Programming and Stuff blog. |
Hi Michael,
Thank you for this article. Is it possible to ask you an advice regarding nested for loop with java 8. Thank you very much. Jade