Enhanced For-loop vs. forEach() in Java 8

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Assuming you have the following list:

List<String> list = Arrays.asList("a", "b", "c", "d", "e", "f");

if you want to do something by using each element in a collection, there are two ways:

1)

list.forEach(s -> System.out.println(s));

2)

for(String s: list){
	System.out.println(s);
}

Both of the above two ways print the elements in sequential:

a
b
c
d
e
f

In this particular case, using lambda expression is not superior than using enhanced for loop.

The main advantage of using the forEach() method is when it is invoked on a parallel stream, in that case we don’t need to wrote code to execute in parallel.

The following code will execute in parallel:

list.parallelStream().forEach(s -> System.out.println(s));

The output could be:

d
f
a
b
c
e

Therefore, whenever parallel execution could possibly improve the performance of the program, the forEach() method should be considered as a good option. You can always do an A/B test for your program and see which way performs better.

2 thoughts on “Enhanced For-loop vs. forEach() in Java 8”

  2. Using parallel execution does not necessary increase performance, especially if your application already multi-threaded, it just takes control of muti-threading out of your hands.

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