在IRB（Interactive Ruby）中，你可以使用以下方法来替换字符串：
1.使用split,然后使用“#{}”（根据情况使用）
" now's the time".split #=> ["now's", "the", "time"],
" now's the time".split(' ') #=> ["now's", "the", "time"]
" now's the time".split(/ /) #=> ["", "now's", "", "the", "time"]
"1, 2.34,56, 7".split(%r{,\s*}) #=> ["1", "2.34", "56", "7"]
"hello".split(//) #=> ["h", "e", "l", "l", "o"]
"hello".split(//, 3) #=> ["h", "e", "llo"]
"hi mom".split(%r{\s*}) #=> ["h", "i", "m", "o", "m"]
"mellow yellow".split("ello") #=> ["m", "w y", "w"]
"1,2,,3,4,,".split(',') #=> ["1", "2", "", "3", "4"]
"1,2,,3,4,,".split(',', 4) #=> ["1", "2", "", "3,4,,"]
"1,2,,3,4,,".split(',', -4) #=> ["1", "2", "", "3", "4", "", ""]
"1:2:3".split(/(:)()()/, 2) #=> ["1", ":", "", "", "2:3"]
"".split(',', -1) #=> []2.使用sub
var1 = "hello world"
var1.sub(/\w+lo/, "hey")output:
"hey world"
3.如果是多处替换，使用gsub
var = "hello world"
=> "hello world"
irb(main):006:0> var.gsub(/\bhello\b/, "Hello")
=> "Hello world"string = "Hello, World!"
new_string = string.gsub("Hello", "Hi")
puts new_string
# 输出: Hi, World!使用正则表达式替换：你也可以使用正则表达式来替换字符串中的内容。
string = "Hello, World!"
new_string = string.gsub(/Hello/, "Hi")
puts new_string
# 输出: Hi, World!4.insert
msg = "Hello world"
=> "Hello world"
irb(main):008:0> msg.insert 5, ","
=> "Hello, world"msg = "Hello world"
=> "Hello world"
irb(main):008:0> msg.insert 5, ","
=> "Hello, world"以上方法可以在IRB中直接使用，你可以根据自己的需求选择适合的方法来替换字符串。