和其他语言的用法大体一致，一般用在多个条件下一个值得判定。

　　需要注意的是powershell里使用注意：

1. 可以通过 -wildcard -regex 来对要判断的值使用通配符或是正则表达式
2. 可以对数组进行判定，遍历数组每一个值
3. 跳出要使用break，否则会全部进行一次条件测试

switch -wildcard ($a)     {         "?14150" {
   "The color is red."; break}         "?14151" {
   "The color is blue."; break}         "?14152" {
   "The color is green."; break}         "?14153" {
   "The color is yellow."; break}         "?14154" {
   "The color is orange."; break}         "?14155" {
   "The color is purple."; break}         "?14156" {
   "The color is pink."; break}        "?14157" {
   "The color is brown."; break}         default {
   "The color could not be determined."}