lesson 2 :特殊符号学习 ！
example ① :
set Z "zhou li "
set Z_LABEL "boy "
puts "$Z_LABEL $Z"
puts "$Z_LABEL $Z"
// 可通过 将特殊符号输出，和C语言一样
example ② :
1. puts "
I have $100.00 bill"
//如果这样会报错 ：提示100.00非法 ps:
是换行
2.
set a 100.00
puts "I have $a bill" ;
//如果这样就不会报错
3.puts "Lincoln is not on the $$a bill" ;# This is OK
//如果在$前面再加一个$ ，将会把$输出
4.puts "Hamilton is not on the $a bill" ;# This is not what you want
//这种会输出$a bill
5.puts "Ben Franklin is on the $$a bill" ;# But, this is OK
//这种情况下可以
6.puts "
................. examples of escape strings"
//学习
是换行
7.puts "Tab Tab Tab"
//学习 是留空格
8.puts "This string prints out
on two lines"
puts "This string comes out
on a single line"
//若一行写不完，可通过这种方式拼接