Introduction
String manipulation is a common task in programming, and Java provides a number of ways to split a string at a specific separator. In this article, we will discuss how to split a string at the n’th occurrence of a specific separator in Java. We will look at various examples and discuss the different approaches to achieve this. We will also discuss the advantages and disadvantages of each approach.
Solution
public static String[] splitAtNthOccurrence(String str, char separator, int n) {
int index = str.indexOf(separator);
int count = 1;
while (index != -1 && count != n) {
index = str.indexOf(separator, index + 1);
count++;
}
if (index == -1) {
return new String[] {str};
}
return new String[] {str.substring(0, index), str.substring(index + 1)};
}
You can do something like this:
Pattern pat = Pattern.compile("((?:[^\u0003]*\u0003){30}[^\u0003]*)\u0003(.*)");
Matcher matcher = pat.matcher(input);
if (matcher.matches()) {
String leftPart = matcher.group(1);
String rightPart = matcher.group(2);
}
The pattern works as follows: The first capture group finds a substring with exactly 30 occurrences of the separator \u0003; the subpattern that finds a substring with no separators, followed by one separator, is repeated 30 times, and this is then followed by another substring with no separators. This must be followed by a separator (the 31st separator), and the second capture group contains everything that’s left in the string. (Note that a parenthesized subpattern that starts with (?: is a non-capture group and does not count in the numbering used by the group() method.)
An alternative is to use the split() method. However, this will require you to reconstruct the left part yourself, by concatenating the first 31 elements of the resulting array (checking first to see if there are actually that many elements), and inserting the separators. Unfortunately, since you’re on Android, you can’t use the String.join() method to help with this, since this was added in Java 8 and Android is still stuck somewhere between Java 6 and Java 7.
Note: I’ve tested this and it works as expected.
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solved How to split a string at the n’th occurrence of a specific separator in Java [closed]
How to Split a String at the n’th Occurrence of a Specific Separator in Java
Splitting a string at a specific separator can be a useful task in Java. In this article, we will look at how to split a string at the n’th occurrence of a specific separator in Java.
Using the String.split() Method
The easiest way to split a string at the n’th occurrence of a specific separator is to use the String.split() method. This method takes a regular expression as an argument and returns an array of strings split at the specified separator.
For example, if we want to split a string at the third occurrence of a comma, we can use the following code:
String[] parts = str.split(",", 3);This will return an array of strings split at the third occurrence of a comma. The first element of the array will be the string before the third comma, the second element will be the string after the third comma, and the third element will be the rest of the string.
Using the StringTokenizer Class
Another way to split a string at the n’th occurrence of a specific separator is to use the StringTokenizer class. This class takes a string and a separator as arguments and returns a StringTokenizer object. This object can then be used to iterate over the tokens in the string.
For example, if we want to split a string at the third occurrence of a comma, we can use the following code:
StringTokenizer st = new StringTokenizer(str, ",");
String[] parts = new String[3];
for (int i = 0; i < 3; i++) {
parts[i] = st.nextToken();
}This will return an array of strings split at the third occurrence of a comma. The first element of the array will be the string before the third comma, the second element will be the string after the third comma, and the third element will be the rest of the string.
Conclusion
In this article, we looked at how to split a string at the n’th occurrence of a specific separator in Java. We saw two different ways to do this: using the String.split() method and using the StringTokenizer class.