Ruby 定义去掉空格的方法整理:
str.gsub(pattern,replacement):替换部分字符串
"hello".gsub(/[aeiou]/, '*') #=> "h*ll*"
"hello".gsub(/([aeiou])/, '<\1>') #=> "h<e>ll<o>"
"hello".gsub(/./) {|s| s.ord.to_s + ' '} #=> "104 101 108 108 111 "
"hello".gsub(/(?<foo>[aeiou])/, '{\k<foo>}') #=> "h{e}ll{o}"
'hello'.gsub(/[eo]/, 'e' => 3, 'o' => '*') #=> "h3ll*"
' he l l o '.gsub(' ','') #=> "hello"
str.strip:返回一个去掉前后空格的字符串
" hello ".strip #=> "hello"
"\tgoodbye\r\n".strip #=> "goodbye"
" hello ".lstrip #=> "hello "
"hello".lstrip #=> "hello"
" hello ".rstrip #=> " hello"
"hello".rstrip #=> "hello"
str.chomp:去掉字符串末尾的 \n \r 或 \r\n
"hello".chomp #=> "hello"
"hello\n".chomp #=> "hello"
"hello\r\n".chomp #=> "hello"
"hello\n\r".chomp #=> "hello\n"
"hello\r".chomp #=> "hello"
"hello \n there".chomp #=> "hello \n there"
"hello".chomp("llo") #=> "he"
str.chop:删除字符串最后一个字符,若结束符是\r\n则两个字符都删除,若字符串为空则返回空
"string\r\n".chop #=> "string"
"string\n\r".chop #=> "string\n"
"string\n".chop #=> "string"
"string".chop #=> "strin"
"x".chop.chop #=> ""
str.ljust(integer,padstr=' '):如果integer大于str长度,返回一个长度为integer,str在左边padstr填充的字符串
"hello".ljust(4) #=> "hello"
"hello".ljust(20) #=> "hello "
"hello".ljust(20, '1234') #=> "hello123412341234123"
str.rjust(integer,padstr=' '):如果integer大于str长度,返回一个长度为integer,str在右边padstr填充的字符串
"hello".rjust(4) #=> "hello"
"hello".rjust(20) #=> " hello"
"hello".rjust(20, '1234') #=> "123412341234123hello"
str.center(width,padstr=' '):如果width大约str长度,返回一个长度为width,str在中间两边padstr填充的字符串
"hello".center(4) #=> "hello"
"hello".center(20) #=> " hello "
"hello".center(20, '123') #=> "1231231hello12312312"