Question

我刚在制片手册里找到这个片子

A variable may be assigned to by a statement of the form

  name=[value]

If value is not given, the variable is assigned the null string.

null 字符串 的确切含义是什么????? 例如。

local empty

等于

local empty=""

?????

Answer 1

“ 核字符串” 是一个零长度的字符串。在您的例子中, 两者是相同的。

简单测试 :

#!/bin/bash
go(){
   local empty
   local empty2=""
   [[ -z $empty ]] && echo "empty is null"
   [[ -z $empty2 ]] && echo "empty2 is null"
   [[ $empty == $empty2 ]] && echo "They are the same"
}

go

指纹 :

empty is null
empty2 is null
They are the same

友情链接