大家来研究下java split函数

gqchen1981 2010-09-26 11:07:14

今天研究了下java split函数:
System.out.println("length1=" + "".split("=").length);
System.out.println("length2=" + "=".split("=").length);
System.out.println("length3=" + "a".split("=").length);
System.out.println("length4=" + "======".split("=").length);
System.out.println("length5=" + "=== ===".split("=").length);
上面的代码大家直接说上面的结果是多少.
(先不要在java环境中运行)
觉得挺好玩的.

...全文

395 12 打赏收藏转发到动态举报

写回复

用AI写文章

12 条回复

切换为时间正序

请发表友善的回复…

发表回复

gqchen1981 2010-09-26

打赏
举报

split重载函数说明:
Splits this string around matches of the given regular expression.

The array returned by this method contains each substring of this string that is terminated by another substring that matches the given expression or is terminated by the end of the string. The substrings in the array are in the order in which they occur in this string. If the expression does not match any part of the input then the resulting array has just one element, namely this string.

The limit parameter controls the number of times the pattern is applied and therefore affects the length of the resulting array. If the limit n is greater than zero then the pattern will be applied at most n - 1 times, the array's length will be no greater than n, and the array's last entry will contain all input beyond the last matched delimiter. If n is non-positive then the pattern will be applied as many times as possible and the array can have any length. If n 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.

The string "boo:and:foo", for example, yields the following results with these parameters:

Regex Limit Result
: 2 { "boo", "and:foo" }
: 5 { "boo", "and", "foo" }
: -2 { "boo", "and", "foo" }
o 5 { "b", "", ":and:f", "", "" }
o -2 { "b", "", ":and:f", "", "" }
o 0 { "b", "", ":and:f" }

An invocation of this method of the form str.split(regex, n) yields the same result as the expression

java.util.regex.Pattern.compile(regex).split(str, n)
See Also:
java.util.regex.Pattern
Parameters:
regex the delimiting regular expression
limit the result threshold, as described above
Returns:
the array of strings computed by splitting this string around matches of the given regular expression
Throws:
PatternSyntaxException - if the regular expression's syntax is invalid
Since:
1.4
@spec
JSR-51