将字符插入字符串的指定区域

Question

如何在代码末尾的注释中打印所需的输出I布局？

string = "matthews"

    # letters = string.split(//)  NOT USING

letter_guess = "t"

if string.include? letter_guess
  print "its there"
else
  print "its not"
end


    # I would then like to ouput this!! --tt---- 

Answer 1

如果您只是替换所有不存在的字母，那实际上非常简单：

if (string.include?(letter_guess))
  puts "It's there: %s" % string.tr('^' + letter_guess', '-')
else
  puts "It's not there."
end

tr方法非常适合在每个字符的基础上删除或更改内容。在这种情况下，它会替换所有不与（^）匹配的字母-。