Traversal of the shell-array

Multiple values can be stored in an array

The shell array is represented by parentheses, and the elements are separated by a "space" symbol.

Syntax format:

Array_name= (value1 value2 ... valuen)

Defining arrays

Array_name[0]=value0

Array_name[1]=value1

Array_name[2]=value2

Reading an array

${array_name[index]}

my_array= (A B "C" D)

echo "first element: ${my_array[0]}"

echo "second element: ${my_array[1]}"

echo "The third element is: ${my_array[2]}"

echo "fourth element: ${my_array[3]}"

Execute the script with the output as follows:

The first element is: A

The second element is: B

The third element is: C

The fourth element is: D

Get all elements in an array

Use @ or * to get all the elements in the array

For example:

my_array= (A B "C" D)

echo "Elements of array: ${my_array[*]}"

echo "Elements of array: ${my_array[@]}"

Execution results

The elements of the array are: A B C D

The elements of the array are: A B C D

Gets the length of the array

y_array= (A B "C" D)
echo "array element number: ${#my_array [*]}"
echo "array element number: ${#my_array [@]}"

Execution results

Number of array elements: 4

Number of array elements: 4

Loop array

For

[[email protected] ~]# array= (a b C 1 2 3)

[[email protected] ~]# echo ${array[@]}

[[Email protected] ~]# a b c d 1 2 3 4

[Email protected] ~]#

For ((i=0;i<${#array [@]};i++))

Do

Echo ${array[i]}

Done

Execution results

A

B

C

1

2

3

Can also be written as

[[email protected] ~]# for a in ${array[@]}

> Do

> Echo $a

> Done

[email protected] ~]# while [$i-lt ${#array [@]}]

> Do

> Echo ${array[$i]}

> Let i++

> Done

Traversal of the shell-array