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Refactoring a for loop into a stream [closed]

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How to change this for loop into stream?
public int calculateForSpliterator(String[] matchTab, String spliterator, RulesChecker rulesChecker) {
int finalScore = 0;
for (String element : matchTab) {
String[] splitScroes = element.split(spliterator);
int ourPoints = Integer.parseInt(splitScroes[0]);
int theirPoints = Integer.parseInt(splitScroes[1]);
finalScore += rulesChecker.checkRules(ourPoints, theirPoints);
}
return finalScore;
}

Assuming RulesChecker#checkRules returns an int, then you can use:
public int calculateForSpliterator(String[] matchTab, String spliterator, RulesChecker rulesChecker) {
return Arrays.stream(matchTab)
.map(element -> element.split(spliterator))
.mapToInt(splitScores -> rulesChecker.checkRules(Integer.parseInt(splitScores[0]),
Integer.parseInt(splitScores[1])))
.sum();
}
Notice how this isn't much more readable than your current solution, so I probably would keep the for-loop if I were you.

Add element to a string [closed]

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I use java and I have the following string:
points="335,234 285,320 185,320 135,234 186,147 285,147 335,233 ";
How it is possible to add 2 to each number?...for example:
points="337,236 287,322 187,322 137,236 188,149 287,149 337,235 ";

You can use String#split to get all the separate numbers in an array, then use a for to iterate through them:
String points = "335,234,285,320,185,320,135,234,186,147,285,147,335,233";
String[] indvPoints = points.split(",");
for(int i = 0; i < indvPoints.length; i++) {
indvPoints[i] = String.valueOf(Integer.parseInt(indvPoints[i]) + 2);
}
points = Arrays.toString(indvPoints).replaceAll("[\\[\\] ]", "");
System.out.println(points);
Although I suggest you just use an int array to begin with, it would be much more efficient and less likely to encounter errors:
int[] points = {335,234,285,320,185,320,135,234,186,147,285,147,335,233};
for(int i = 0; i < points.length; i++) {
points[i] += 2;
}
System.out.println(Arrays.toString(points));

How tho check in Java if there is same characters in a String? [closed]

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I've got a 6 char long string, and I would like to check, if there is just one from each character. How to?

You could compare the number of distinct characters to the length of the string:
boolean charMoreThanOnce = s.chars().distinct().count() < s.length();

You can do it using a Set. You need unique elements and Set gurantees you containing the unique elements. HashSet is implementation of Set, you can use it to implement this idea.
public boolean ifAllCharsUnique(String input){
char[] arr = input.toCharArray();
int length = arr.length;
Set<Character> checker = new HashSet<>();
for(int i =0 ; i < length; i++){
if(checker.contains(arr[i]){
return false;
}
checker.add(arr[i]);
}
return true;
}

How to substract two strings [closed]

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I have started learning Java and have some across some difficulties. I'm trying to subtract two strings.
for example, with these strings;"032"&&"100". I want to be able to subtract each number individually so that the answer would be "032".
I have tried using substring, and parsing the two values to ints, but don't know what to do next. I have also tries using a for loop, to go through each arrays of the strings.
I do not expect for anyone to do this for me, but I would love to get some insight,or to tell me that i'm headed in the right direction
thanks
public static String appliquerCoup( String combinaison, String coup ) {
String nouveauCoup="";
if(combinaison!=null&&coup!=null){
for(int i=0;i>combinaison.length();i++){
int a = Integer.parseInt(combinaison.substring(i, i + 1));
int b = Integer.parseInt(coup.substring(i, i + 1));
nouveauCoup=String.valueOf(a-b);
if(a-b<0){
nouveauCoup=0;
}
}
} // main
return nouveauCoup;
}

If I understand you question correctly. you want to subtract each digit individually.
So (0-1), (3-0), (2-0). The following program does this (yields -132):
public static void main(String[] args) {
String A = "032";
String B = "100";
String str = "";
for(int i = 0; i < A.length(); i++)
{
int a = Integer.parseInt(A.substring(i, i + 1));
int b = Integer.parseInt(B.substring(i, i + 1));
int c = a - b;
str += String.valueOf(c < 0 ? 0 : c);
}
System.out.println(str);
}
Essentially, extract the i-th character of each string, convert them to integers, then do the subtraction. Convert the result back to a string and append it to the result string.

Comparing multiple strings in Java [closed]

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I have 5 distinct strings called, say, string1 through string5.
I want to write a simple if statement that runs if any two of the five strings contain the same string. How would I do that?
Thanks in advance!

Comparison is a binary operation, therefore you can always compare only two objects at a time. I would suggest using a cycle and comparing each string to the remaining ones.
public boolean multipleStringEquals(String[] strings) {
for (int i = 0; i < strings.length; i++) {
for (int j = i + 1; j < strings.length; j++) {
if (strings[i].equals(strings[j])) {
return true;
}
}
}
return false;
}