从bash shell脚本循环访问数组索引变量？

Question

I want to access the array index variable while looping thru an array in my bash shell script.

myscript.sh

0
1
2
3

Actual result

 foo bar baz bat 

Desired result

 0 1 2 3 

How do I alter my script to achieve this?

Answer 1

You can loop over index using indirect reference syntax ( since Bash 3 ) :

#!/bin/bash

A=('foo' 'bar' 'baz' 'bat')
for i in ${!A[*]}; do # replace ${A[*]} with ${!A[*]}
  echo $i
done

For more : How to iterate over associative arrays in Bash