Array Learning of Bash scripts

indexed arrays and associative arrays can be used in bash, and bash adds support for associative arrays after version 4.0

First, an indexed array

1. Defining an indexed array

# Way 1array_value= (1 2 3 4 5 6)
Or
Array_value= (1, 2, 3, 4, 5, 6) # way 2array_value[0]= ' test1 ' array_value[2]= ' test2 ' ... array_value[5]= ' test6 '

As with other scripting languages, the starting position of an indexed array in bash starts at 0

2. Print an array of items

echo ${array_value[0]} or Index=5echo ${array_value[$index]}

The printing results are as follows:

3. Print all values of the array

echo ${array_value[*]} or echo ${array_value[@]}

The printing results are as follows:

4. Print array length

echo ${#array_value [*]} or echo ${#array_value [@]} Note the difference between the length of the printed array and the length of the string if the echo ${#array_value} is used to obtain a result of 1, it is not the correct result

The printing results are as follows:

Error mode:

Second, associative array

1. Defining Associative arrays

# define associative array assoc_arraydeclare-a Assoc_array

2. Inserting elements

assoc_array= ([Index1]=val1 [Index2]=val2] or Assoc_array[index1]=val1assoc_array[index2]=val2

For example:

3. List the array index

echo ${!assoc_array[*]} or Echo ${!assoc_array[@]} This method also applies to indexed arrays

The results are as follows:

Array Learning of Bash scripts