Use of split() method in string class

First explain split（String regex,int limit）
First look at the official explanation ：

Official explanation ：
public String[] split(String regex,
int limit) Split this string into the given regular expression The matching of . The array returned by this method contains each substring of this string , The string is terminated by another substring that matches the given expression , Or terminated by the end of the string .
The substrings in the array are arranged in their order in this string . If the expression does not match any part of the input , The generated array has only one element , That is, this string .

When there is a positive width match at the beginning of this string , Contains an empty leading substring at the beginning of the result array . Zero width matching at the beginning will not produce such an empty leading substring .

limit The parameter controls the number of times the mode is applied , Therefore, the length of the generated array is affected . If the limit n Greater than 0, The mode can be applied at most n -1 Time , The length of the array is not greater than n
, The last entry of the array will contain all inputs beyond the last matching delimiter . If n Right and wrong , Then the pattern will be applied as many times as possible , And the array can have any length .
If n by 0, The pattern will be applied as many times as possible , Arrays can have any length , And the trailing empty string will be discarded .

understand ： Is to satisfy the string regex The part of the string is replaced by an empty string and split from here , And convert it into an array

String Regex Is a regular expression ,limit Is the number of cuts

Now? limit There are three situations ：1. Positive numbers 2. negative 3. be equal to 0

Positive numbers ：

split Method will cut the string （limit-1） Time , That is to say, if limit =
1, that split The array length is 1, Is the original string , It just becomes an array . And that is regex Does not satisfy any characters in the string , It will also convert the original string into an array , If it is 2 Words , Then it will cut 1 Time , If it is 3 Words , cutting 2 Time

negative ：

split Will cut an infinite number of times , That is, all the strings that satisfy regex Replace all with empty strings , Converted to an array
Whether it's -1 still -10, The result is the same

0：

split It also cuts an infinite number of times , Also, all the strings that satisfy regex Replace all with empty strings , But the empty string at the end of the string will be cleared and converted into an array

Look again. split（String regex）, Is a default limit yes 0 Of split（String regex,int limit）

Yes split（） The understanding of the method is a step deeper ,nice