I want to compare two arrays(same sized) of strings and check that mainArray contains elements in subArray depending on its index;

public static void main(String[] args) {
    List<String> mainArray = Arrays.asList("Red book", "Yellow bird", "Green sky");
    List<String> subArray = Arrays.asList("Red", "Yellow", "Green");

    boolean flag = false;
    for (int i = 0; i < mainArray.size(); i  ) {
        flag = mainArray.get(i).contains(subArray.get(i));
        if(!flag){
            break;
        }
    }
}
//returns true

this looks ugly is where any solution with stream.filter or something?

CodePudding user response：

This will work whether the two arrays (actually Lists in your case) are equal size or not.

• first stream the mainArray.
• then flatMap the subArray
• the filter those cases where the mainArray string contains one of the subArray strings.
• count the successes and return whether it equals the main array size.

boolean flag = mainArray.stream()
        .flatMap(str -> subArray.stream()
                .filter(sa -> str.contains(sa)))
        .count() == mainArray.size();

Here is a demo using a single sub Array and multiple main arrays

List<String> mainArray1 =
        List.of("Red book", "Purple bird", "Blue sky");
List<String> mainArray2 = List.of("Red book", "Blue bird",
        "Blue sky", "Violet flower");
List<String> mainArray3 = List.of("Red book", "Blue bird");
List<String> mainArray4 =
        List.of("Blue book", "Blue bird", "Blue sky");
List<String> mainArray5 = List.of("Red book", "Purple color");
List<String> mainArray6 = List.of("Red book", "Blue bird",
        "Blue sky", "Orange orange");

List<List<String>> lists = List.of(mainArray1, mainArray2,
        mainArray3, mainArray4, mainArray5, mainArray6);

List<String> subArray = List.of("Red", "Yellow", "Blue",
        "Orange", "Violet", "Green");

int i = 1;
for (List<String> mainArray : lists) {
    
    boolean flag = mainArray.stream()
            .flatMap(str -> subArray.stream()
                    .filter(sa -> str.contains(sa)))
            .count() == mainArray.size();
    
    System.out.printf("mainArray%d %b%n", i  , flag);
}

Prints

mainArray1 false
mainArray2 true
mainArray3 true
mainArray4 true
mainArray5 false
mainArray6 true

CodePudding user response：

I found this solution

IntStream.range(0, mainArray.size()).allMatch(i -> mainArray.get(i).contains(subArray.get(i)));