shell中遍历数组的几种方式

#!/bin/bash
 
arr=(  '你好')
length=${#arr}
echo "长度为：$length"
 
# for 遍历
for item in ${arr[*]}
do
 echo $item
 
done
 
i=
 
# until遍历
echo until begin
 
until (( i++  > $length ))
 
do
 echo ${arr[(( i- ))]}
done
 
echo end
 
# for遍历
 
echo for  begin
 
for (( k=; k <= $length; k++ ))
 
do
 echo ${arr[$k]}
 
done
 
i=
 
echo while begin
 
#while遍历
 
while (( i++ <= $length  ))
do
 echo ${arr[(( i- )) ]}
 
done