CODEWITHSUNDEEP
javaarraysjava-8comparator
Karan mehta
Karan mehta

Reputation: 89

Sort an array of String based on a name pattern

I want to sort an array of strings by whether they contain a custom pattern or not.

I have tried custom sort using comparator, but they all sort based on ascending or descending order. My requirement is as follows:

String[] strArr = { "maven", "maven_apache", "java", "multithreading", "java_stream" };
String patternToMatch = "java";

Then output should be a sorted array with strings containing the pattern java first, followed by the others:

String[] strArr = { "java", "java_stream", "maven", "maven_apache", "multithreading" };

Upvotes: 6

Views: 1355

Answers (2)

Eugene
Eugene

Reputation: 121078

As simple as defining a Comparator and sorting the elements based on it:

Arrays.sort(strArr, Comparator.comparing(x -> !x.startsWith("java")));

Upvotes: 8

Dorian
Dorian

Reputation: 11

I think this can work for you. You can use it to determine if the string starts with "java", then swap it to the first know "non-java" of the array if it returns true.

public boolean startsWith(String prefix, int toffset)

Tests if the substring of this string beginning at the specified index starts with the specified prefix. Parameters: prefix - the prefix. toffset - where to begin looking in this string.

Returns: true if the character sequence represented by the argument is a prefix of the substring of this object starting at index toffset; false otherwise. The result is false if toffset is negative or greater than the length of this String object; otherwise the result is the same as the result of the expression 

      this.substring(toffset).startsWith(prefix)

Upvotes: 0

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