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JAVA : Check if Collection of object with start and end dates are overlapping - best way [closed]

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I've multiple List of Java-Datetimes with MyCustomDate object contains ( start DateTime and end DateTime ) LocalDateTime with hours and seconds.
I need to write function to check if There is Overlapping dates in my list return true \ false - with the best performance
can use java8 (stream functions)

You have to test all ranges aginst each other. There is no other way. Try this way, although is just one implementation, there are plenty of correct ways to implement it:
public boolean isThereOverlapingRanges(List<CustomDateRange> ranges) {
if (ranges.size() <= 1) {
return false;
}
boolean overlaping = false;
for(int i = 1; i < ranges.size(); i++) {
if (isDateInRange(ranges.get(0).start(), ranges.get(i)) ||
isDateInRange(ranges.get(0).end(), ranges.get(i))) {
overlaping = true;
break;
}
}
return overlaping || isThereOverlapingRanges(ranges.subList(1, ranges.size());
}
private boolean isDateInRange(DateTime date, CustomDateRange range) {
return date.after(range.start()) && date.before(range.end());
}

data structure is range or tuple [closed]

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I am trying to convert the following Java code into swift, but I do not know about this data structure new (int start, int end)[input. length], any guidance would be appraciated.
public override void collection_entries(int[] input)
{
var ranges = new (int start, int end)[input.length];
}

In swift, you should use a Range().
let start = 0
let end = 6
var ranges = Range(start...end)[input.count]

Stack forEach expression to loop for difference between existing size and new one [closed]

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I have a class with data member:
private static final int DEFAULT_SIZE = 10;
private Stack<String> myStack = new Stack<>();
// want to add more element to the stack based on demand - but add incremental demand
public void addCapacity(int incremental) {
int diff = incremental - DEFAULT_SIZE;
myStack.forEach((diff) -> {
myStack.push("something");
});
}
The idea was to see if this forms a use case for lambda functions. But it will not allow me as it is expecting a boolean in place of diff. Is lambda forEach a use-case here?

Since Stack extends Vector, if you wanted to increase the capacity, then you could have used ensureCapacity (in Vector)
myStack.ensureCapacity(minCapacity);
If you wanted to do myStack.push("something") diff times, then you could have used:
IntStream.range(0, diff).forEach(i -> myStack.push("something"));

For each Loop in Java 8 : What is the best way to write the following code in Java 8 [closed]

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What is the best way to write the following code in Java 8 in terms of for loop and filtering.
boolean flag = true;
List<Feed> availableFeeds = data.getAvailableFeeds();
for (Feed feedElement : availableFeeds) {
String type = feedElement.getType();
if ("MatchState".equals(type)) {
flag = false;
break;
}
}

boolean flag = data.getAvailableFeeds()
.stream()
.map(Feed::getType)
.noneMatch("MatchState"::equals)
The first line creates a stream out of the list. The second one maps each Feed to type by calling getType. The last one returns true if there is no type that equals the string "MatchState".

You need filtering and a short break:
boolean flag = !availableFeeds.stream()
.map(Feed::getType)
.anyMatch(type -> "MatchState".equals(type));
or:
boolean flag = availableFeeds.stream()
.map(Feed::getType)
.allMatch(type -> !"MatchState".equals(type));

One way to do it is:
boolean flag = !data.getAvailableFeeds()
.stream()
.filter(Objects::nonNull)
.anyMatch(feed -> feed.getType().equals("MatchState"));
This example constructs a Stream<Feed> from the List<Feed> returned by getAvailableFeeds(), and then calls Stream<Feed>.anyMatch() which accepts a Predicate<Feed> as it's parameter, in this case the predicate is a feed where the feed is not null, and the feed's type returned by Feed.getType() equals "MatchState"

If statement based on what boolean method returns [closed]

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I am trying to use this boolean method in my app. I want to use what it returns in an if statement so if it returns true I can do something. Something like
if(isNook() == True) {
//do something
}
I'm sure the answer is obvious but I couldn't find anything on how to do this.

Why don't you use:
if (isNook()) {
// do something
}

People are suggesting this:
if (isNook()) {
// do something
}
which is correct. However, we need to discuss your attempt. This was it:
if(isNook() == True) {
// do something
}
In Java, boolean variables are represented with true and false - NOT True and False - the values are case sensitive.
To contrast, for example, Python uses the values True and False
Your attempt should have been this:
if(isNook() == true) {
// do something
}

Try this:
boolean bool_result;
if(bool_result = isNook( )) {
// do stuff with bool_result here
}
result can actually be other data types (i.e. int/char/string) as long as it evaluates to true or false.