Bash Shell array variables

First, define the array variable

1. Grammar

(1) arrayname= (parameter1 parameter2 ...)

Example 1, define an array named name, with a value of Claire,obama,george

Name= (Claire Obama )

(2) Arrayname= (

Parameter1

Parameter2

...

)

Again we change example 1 to the second way

Name= (

Claire

Obama

George

)

Second, access to functions

(1) Subscript access

${ARRAYNAME[0]} Example 1 is Claire.

${ARRAYNAME[1]} Example 1 is Obama.

${ARRAYNAME[2]} Example 1 is George.

${arrayname[n]}

(2) @ and * access

${arrayname[@]} and ${arrayname[*]} get the elements in the array, example 1 is Claire Obama George

Third, get the number of arrays

(1) Get the number of the entire array

${#ArrayName [@]} and ${#ArrayName [*]} Example 1 is 3,

(2) Get the number of individual elements

${#ArrayName [0]} Example 1 is 5.

${#ArrayName [1]} Example 1 is 4.

${#ArrayName [2]} Example 1 is 5.

Iv. iterating through an array

(1) using while traversal

I=0

While [$i-lt ${#ArrayName [*]}]

Do

echo "parameter is: ${arrayname[$i]}"

((i++))

Done

(2) using for traversal

For parameter in ${arrayname[*]}

Do

echo "parameter is: $parameter"

Done

V. Emptying an array

(1) emptying a single array

arrayname[n]=

Note: When emptying a single array, the length of the array does not change

(2) Empty the entire array

1.unset Arrayname

2.arrayname=

Bash Shell array variables