Tcl命令操做实验-----(11)--- 过程

TCL的过程：

Vivado% proc factorial {number} {
if {$number <=  1}  {
   return 1
}
return  [expr $number * [factorial [expr $number - 1]]]
}
Vivado% puts [factorial 3]
6

我发现一个参数好象不 能设为默认 参考：

Vivado% proc factorial {number {5} } {
if {$number <=  1}  {
   return 1
}
return  [expr $number * [factorial [expr $number - 1]]]
}
Vivado% puts  [factorial ]
wrong # args: should be "factorial number 5"
Vivado% puts  [factorial {3 5}]
wrong # args: should be "factorial number 5"
Vivado% puts  [factorial {3}]
wrong # args: should be "factorial number 5"