ruby 字符串学习2

时间：2023-03-08 19:45:36

在一个ruby字符串中包含表但是或者变量。想使用不同的值替换表达式或者变量

1 类似java 或者python的printf-style方式

template = 'Oceania has always been at war with %s.'

template % 'Eurasia' # => "Oceania has always been at war with Eurasia."

template % 'Eastasia' # => "Oceania has always been at war with Eastasia."

'To 2 decimal places: %.2f' % Math::PI # => "To 2 decimal places: 3.14"

'Zero-padded: %.5d' % Math::PI  # => "Zero-padded: 00003"

2 或者使用erb，因为我用的ide，所以最后一行使用的是kernel.binding ，如果你在irb中，可以只使用binding

require 'erb'

template = ERB.new %q{Chunky <%= food %>!}

food = "bacon"

puts output = template.result(Kernel.binding)

3翻转字符串

s = ".sdrawkcab si gnirts sihT"

s.reverse # => "This string is backwards."

s  # => ".sdrawkcab si gnirts sihT"

s.reverse! # => "This string is backwards."

s  # => "This string is backwards."
s = "order. wrong the in are words These"

s.split(/(\s+)/).reverse!.join('') # => "These words are in the wrong order."

s.split(/\b/).reverse!.join('') # => "These words are in the wrong. order"

(\s+)和\s+区别，(\s+)匹配的空格会包含返回列表中

"Three little words".split(/\s+/)

# => ["Three", "little", "words"]

"Three little words".split(/(\s+)/)

# => ["Three", " ", "little", " ", "words"]

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