引用:str = IO.read("allset1.txt")
puts str.length
puts str[0,30]
读到一个数组里面
引用:arr = IO.readlines("allset1.txt")
puts arr.length
puts arr[2]
IO会自动关闭释放内存的
引用:str = IO.read("allset1.txt")
puts str.length
puts str[0,30]
引用:arr = IO.readlines("allset1.txt")
puts arr.length
puts arr[2]