取值
1. 取字符串中的某些值
a. $a = '123456789'
$a.substring($a.length - 3, 3)
789
b. '123456'.Substring(3, 2)
45
2. 移除字符串前后的空格
a.
$text = ' Hello '
$text.Trim()
b. 移除字符串前后的空行
$text = '
Hello
'
$text.Trim()
c. 移除白空格,原点,短划线,和行分隔符(剥洋葱,从外到内)
$text = '
... Hello
...---
'
$text.Trim(" .-`t`n`r")