Check out example codes for "loop in java 8". It will help you in understanding the concepts better.

Code Example 1

List<Integer> data = new ArrayList<>();

//Indexed Loop
for(int i = 0,size=data.size();i<size;i++){
	System.out.println(data.get(i));  
}

//For each loop
for(Integer element : data){
	System.out.println(element);
}

//Using forEach
data.forEach(System.out::println);

//Using Stream
data.stream().forEach(System.out::println)
  
//While loop
int i = 0;
while(i<data.size()){
	System.out.println(data.get(i++));  
}

Code Example 2

List<String> someList = new ArrayList<String>();
// add "monkey", "donkey", "skeleton key" to someList
for (String item : someList) {
    System.out.println(item);
}

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