String.scan和String.split之间的区别

Question

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

Answer 1

它们用于完全不同的目的. String#scan用于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用于根据分隔符将字符串拆分为数组.分隔符可以是静态字符串(比如;在单个分号上分割)或正则表达式(比如/\s/+在任何空白字符上分割).

输出String#split不包括分隔符.相反,除了分隔符,一切都会在输出数组中被返回,而输出String#scan将只包括什么是分隔符匹配.

# 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: ["|", "|"]

上述两者也会接受正则表达式来代替简单字符串"|".

# 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"]