bash + for循环+输出索引号和元素

Question

这是我的阵列:

$ ARRAY=(one two three)

如何打印数组,以便输出如下:index i, element[i]使用我在下面使用的printfor for循环

1,one
2,two
3,three

一些注意事项供我参考

1种打印阵列的方法:

$ printf "%s\n" "${ARRAY[*]}"
one two three

2种打印阵列的方法

$ printf "%s\n" "${ARRAY[@]}"
one
two
three

3种打印阵列的方法

$ for elem in "${ARRAY[@]}"; do  echo "$elem"; done
one
two
three

4种打印阵列的方法

$ for elem in "${ARRAY[*]}"; do  echo "$elem"; done
one two three

一种看待阵列的方式

$ declare -p ARRAY
declare -a ARRAY='([0]="one" [1]="two" [2]="three")'

Answer 1

你可以遍历数组的索引,即从0到${#array[@]} - 1.

#!/usr/bin/bash

array=(one two three)

# ${#array[@]} is the number of elements in the array
for ((i = 0; i < ${#array[@]}; ++i)); do
    # bash arrays are 0-indexed
    position=$(( $i + 1 ))
    echo "$position,${array[$i]}"
done

产量

1,one
2,two
3,three

Answer 2

最简单的迭代方法似乎是:

#!/usr/bin/bash

array=(one two three)

# ${!array[@]} is the list of all the indexes set in the array
for i in ${!array[@]}; do
  echo "$i, ${array[$i]}"
done