puts 在屏幕上输出指定的字符串，并以回车结束
print 和puts的功能一样，不以回车结束
printf 格式化输出，类似C语言和Java
puts "puts works"
puts " with line breaks."
print "print works"
print " with no line breaks."
printf("\n\nprintf formats numbers like %7.2f, and
strings like %s.",3.14156,"me")
输出结果如下
puts works with line breaks. print works with no line breaks. printf formats numbers like 3.14, and strings like me.
开心洋葱 , 版权所有丨如未注明 , 均为原创丨未经授权请勿修改 , 转载请注明ruby在屏幕上输出字符串的几种方法！
