基于Bash脚本中的关联数组，我需要遍历它以获得键和值。
#!/bin/bash
declare -A array
array[foo]=bar
array[bar]=foo
我实际上不明白如何在使用for-in循环时获得键。
当前回答
declare -a arr
echo "-------------------------------------"
echo "Here another example with arr numeric"
echo "-------------------------------------"
arr=( 10 200 3000 40000 500000 60 700 8000 90000 100000 )
echo -e "\n Elements in arr are:\n ${arr[0]} \n ${arr[1]} \n ${arr[2]} \n ${arr[3]} \n ${arr[4]} \n ${arr[5]} \n ${arr[6]} \n ${arr[7]} \n ${arr[8]} \n ${arr[9]}"
echo -e " \n Total elements in arr are : ${arr[*]} \n"
echo -e " \n Total lenght of arr is : ${#arr[@]} \n"
for (( i=0; i<10; i++ ))
do echo "The value in position $i for arr is [ ${arr[i]} ]"
done
for (( j=0; j<10; j++ ))
do echo "The length in element $j is ${#arr[j]}"
done
for z in "${!arr[@]}"
do echo "The key ID is $z"
done
~
其他回答
欢迎使用输入关联数组2.0!
clear
echo "Welcome to input associative array 2.0! (Spaces in keys and values now supported)"
unset array
declare -A array
read -p 'Enter number for array size: ' num
for (( i=0; i < num; i++ ))
do
echo -n "(pair $(( $i+1 )))"
read -p ' Enter key: ' k
read -p ' Enter value: ' v
echo " "
array[$k]=$v
done
echo " "
echo "The keys are: " ${!array[@]}
echo "The values are: " ${array[@]}
echo " "
echo "Key <-> Value"
echo "-------------"
for i in "${!array[@]}"; do echo $i "<->" ${array[$i]}; done
echo " "
echo "Thanks for using input associative array 2.0!"
输出:
Welcome to input associative array 2.0! (Spaces in keys and values now supported)
Enter number for array size: 4
(pair 1) Enter key: Key Number 1
Enter value: Value#1
(pair 2) Enter key: Key Two
Enter value: Value2
(pair 3) Enter key: Key3
Enter value: Val3
(pair 4) Enter key: Key4
Enter value: Value4
The keys are: Key4 Key3 Key Number 1 Key Two
The values are: Value4 Val3 Value#1 Value2
Key <-> Value
-------------
Key4 <-> Value4
Key3 <-> Val3
Key Number 1 <-> Value#1
Key Two <-> Value2
Thanks for using input associative array 2.0!
输入关联数组1.0
(不支持包含空格的键和值)
clear
echo "Welcome to input associative array! (written by mO extraordinaire!)"
unset array
declare -A array
read -p 'Enter number for array size: ' num
for (( i=0; i < num; i++ ))
do
read -p 'Enter key and value separated by a space: ' k v
array[$k]=$v
done
echo " "
echo "The keys are: " ${!array[@]}
echo "The values are: " ${array[@]}
echo " "
echo "Key <-> Value"
echo "-------------"
for i in ${!array[@]}; do echo $i "<->" ${array[$i]}; done
echo " "
echo "Thanks for using input associative array!"
输出:
Welcome to input associative array! (written by mO extraordinaire!)
Enter number for array size: 10
Enter key and value separated by a space: a1 10
Enter key and value separated by a space: b2 20
Enter key and value separated by a space: c3 30
Enter key and value separated by a space: d4 40
Enter key and value separated by a space: e5 50
Enter key and value separated by a space: f6 60
Enter key and value separated by a space: g7 70
Enter key and value separated by a space: h8 80
Enter key and value separated by a space: i9 90
Enter key and value separated by a space: j10 100
The keys are: h8 a1 j10 g7 f6 e5 d4 c3 i9 b2
The values are: 80 10 100 70 60 50 40 30 90 20
Key <-> Value
-------------
h8 <-> 80
a1 <-> 10
j10 <-> 100
g7 <-> 70
f6 <-> 60
e5 <-> 50
d4 <-> 40
c3 <-> 30
i9 <-> 90
b2 <-> 20
Thanks for using input associative array!
使用这个高阶函数来防止厄运金字塔
foreach(){
arr="$(declare -p $1)" ; eval "declare -A f="${arr#*=};
for i in ${!f[@]}; do $2 "$i" "${f[$i]}"; done
}
例子:
$ bar(){ echo "$1 -> $2"; }
$ declare -A foo["flap"]="three four" foo["flop"]="one two"
$ foreach foo bar
flap -> three four
flop -> one two
使用感叹号访问键:${!数组[@]}，则使用${array[@]}访问这些值。
你可以像这样遍历键/值对:
for i in "${!array[@]}"
do
echo "key : $i"
echo "value: ${array[$i]}"
done
注意for语句中变量周围使用了引号(加上使用@而不是*)。这在任何键包含空格的情况下都是必要的。
另一个答案中的混淆来自于这样一个事实，即您的问题在键和值中都包含了“foo”和“bar”。
declare -a arr
echo "-------------------------------------"
echo "Here another example with arr numeric"
echo "-------------------------------------"
arr=( 10 200 3000 40000 500000 60 700 8000 90000 100000 )
echo -e "\n Elements in arr are:\n ${arr[0]} \n ${arr[1]} \n ${arr[2]} \n ${arr[3]} \n ${arr[4]} \n ${arr[5]} \n ${arr[6]} \n ${arr[7]} \n ${arr[8]} \n ${arr[9]}"
echo -e " \n Total elements in arr are : ${arr[*]} \n"
echo -e " \n Total lenght of arr is : ${#arr[@]} \n"
for (( i=0; i<10; i++ ))
do echo "The value in position $i for arr is [ ${arr[i]} ]"
done
for (( j=0; j<10; j++ ))
do echo "The length in element $j is ${#arr[j]}"
done
for z in "${!arr[@]}"
do echo "The key ID is $z"
done
~
您可以使用${!数组[@]}:
bash-4.0$ echo "${!array[@]}"
foo bar
然后，遍历键/值对很容易:
for i in "${!array[@]}"
do
echo "key :" $i
echo "value:" ${array[$i]}
done
