String.scan 和 String.split 的区别 [英] Difference between String.scan and String.split

问题描述

Ruby 中这两个(String#scan 和 String#split)有什么区别?

What is the difference between these two (String#scan and String#split) in Ruby?

推荐答案

它们的用途完全不同.使用 String#scan从字符串中提取正则表达式的匹配项并返回数组中的匹配项，而 String#split 旨在根据分隔符将字符串拆分为数组.分隔符可以是一个静态字符串(如 ; 在单个分号上拆分)或正则表达式(如 /\s/+ 在任何空白字符上拆分).

They serve entirely different purposes. String#scan is used to extract matches of a regular expression from a string and return the matches in an array, while String#split is intended to split a string up into an array, based on a delimiter. The delimiter may be either a static string (like ; to split on a single semicolon) or a regular expression (like /\s/+ to split on any whitespace characters).

String#split 的输出不包括分隔符.相反，除分隔符之外的所有内容都将在输出数组中返回，而 String#scan 的输出将只包括与分隔符匹配的内容.

The output of String#split doesn't include the delimiter. Rather, everything except the delimiter would be returned in the output array, while the output of String#scan would only include what is matched by the delimiter.

# A delimited string split on | returns everything surrounding the | delimiters
"a|delimited|string".split("|")
# Prints: ["a", "delimited", "string"]

# The same string scanninng for | only returns the matched |
"a|delimited|string".scan("|")
# Prints: ["|", "|"]

以上两种方法也都接受一个正则表达式来代替简单的字符串 "|".

Both of the above would also accept a regular expression in place of the simple string "|".

# Split on everything between and including two t's
"a|delimited|string".split(/t.+t/)
# Prints: ["a|delimi", "ring"]

# Search for everything between and including two t's
"a|delimited|string".scan(/t.+t/)
# Prints: ["ted|st"]

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