java .split() method gives arrays of different lengths-CodePudding

I am reading lines from a tsv file, and then trying to delimit them by words = array.split("\t")

words is an array that i have already initiated by String[] words = {"0", "0", "0", "0", "0", "0"} so it has a fixed length of 6. However, words[i] can have a different length of words[j]. I absolutely want words to have its length fixed to 6. Why is that happening and how do i fix this?

Tried for(int i=0; i<x; i ){ String[] words = new String[6] }

CodePudding user response：

String.split has an override you can use to limit the output. It will grab the first n number of the string and then stop.

From the documentation:

The limit parameter controls the number of times the pattern is applied and therefore affects the length of the resulting array.

If the limit is positive then the pattern will be applied at most limit - 1 times, the array's length will be no greater than limit, and the array's last entry will contain all input beyond the last matched delimiter.

If the limit is zero then the pattern will be applied as many times as possible, the array can have any length, and trailing empty strings will be discarded.

If the limit is negative then the pattern will be applied as many times as possible and the array can have any length.

Here's an example

String[] splitWithoutLimit = "Column1,Column2,Column3".split(",")

// splitWithoutLimit will contain the following values:
// { "Column1", "Column2", "Column3" }

String[] splitWithLimit = "Column1,Column2,Column3".split(",", 2)

// splitWithLimit will contain the following values:
// { "Column1", "Column2,Column3" }

CodePudding user response：

Splitting a string, taking maximum 6 values, and filling an array with the "0" string if there are too few values.

        String[] defaultWords = {"0", "0", "0", "0", "0", "0"};
        int fixedSize = defaultWords.length;
        String[] words = new String[fixedSize];

        // reading
        String str = "1\t2\t3";
        String[] tmpWords = str.split("\t");
        System.arraycopy(defaultWords, 0, words, 0, fixedSize);
        System.arraycopy(tmpWords, 0, words, 0, Math.min(fixedSize, tmpWords.length));

        System.out.println(Arrays.toString(words));

Result:

[1, 2, 3, 0, 0, 0]