Arrays

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Lab

This is the original contents of the lab file (../labs/03-arrays/03-arrays.lab.sh).

Follow the instructions in the file to solve the lab.

# Assume "LAB03A_INDEXED_ARRAY" is passed as the "$1" positional parameter
LAB03A_INDEXED_ARRAY=( "zero" "one" "two" "three" )
LAB03A_INDEXED_ARRAY+=( "four" )
LAB03A_INDEXED_ARRAY[6]="six"
LAB03A_INDEXED_ARRAY+=( "mystery" )
export LAB03A_INDEXED_ARRAY

# Assume "LAB03A_INDEX_NUMBER" is passed as the "$2" positional parameter
# Figure out which index number to set below to make the function return 0.
LAB03A_INDEX_NUMBER=""
export LAB03A_INDEX_NUMBER

# Assume "LAB03A_INDEX_VALUE" is passed as the "$3" positional parameter
LAB03A_INDEX_VALUE="mystery"
export LAB03A_INDEX_VALUE

sobash_assert_index_array_element_contains_value() {

  local -n my_indexed_array
  local -n index_number
  local -n index_value

  my_indexed_array="$1"
  index_number="$2"
  index_value="$3"

  if [[ "$#" == "0" ]]; then
    echo -e "\n[FAIL] ${FUNCNAME[0]} | Failed to pass arguments to function."
    return 1
  fi

  if [[ "${my_indexed_array[$index_number]}" != "${index_value}" ]]; then
    echo -e "\n[FAIL] ${FUNCNAME[0]} | Value (${my_indexed_array[$index_number]}) from array element (${index_number}) does not match provided index value (${index_value})." 1>&2
    return 2
  else
    echo -e "\n[INFO] ${FUNCNAME[0]} | Value (${my_indexed_array[$index_number]}) from array element (${index_number}) does match provided index value (${index_value})."
    return 0
  fi

}

# Assume "LAB03_ASSOCIATIVE_ARRAY" is passed as the "$1" positional parameter
declare -A LAB03B_ASSOCIATIVE_ARRAY
LAB03B_ASSOCIATIVE_ARRAY=( [zero]="zero" [one]="one" [two]="two" [three]="three" )
LAB03B_ASSOCIATIVE_ARRAY+=( [four]="four" )
LAB03B_ASSOCIATIVE_ARRAY[six]="six"

# Figure out if this last type of assignment sets the element key, value, or both,
# and then update LAB03B_ELEMENT_KEY and LAB03B_ELEMENT_VALUE, as needed.
# shellcheck disable=SC2190
LAB03B_ASSOCIATIVE_ARRAY+=( "seven" )
export LAB03B_ASSOCIATIVE_ARRAY

# Assume "LAB0B_ELEMENT_KEY" is passed as the "$2" positional parameter
LAB03B_ELEMENT_KEY="seven"
export LAB03B_ELEMENT_KEY

# Assume "LAB03A_ELEMENT_VALUE" is passed as the "$3" positional parameter
LAB03B_ELEMENT_VALUE="seven"
export LAB03B_ELEMENT_VALUE

sobash_assert_associative_array_element_contains_value() {

  local -n my_associative_array
  local -n element_key
  local -n element_value

  my_associative_array="$1"
  element_key="$2"
  element_value="$3"

  if [[ "$#" == "0" ]]; then
    echo -e "\n[FAIL] ${FUNCNAME[0]} | Failed to pass arguments to function."
    return 1
  fi

  if [[ "${my_associative_array[$element_key]}" != "${element_value}" ]]; then
    echo -e "\n[FAIL] ${FUNCNAME[0]} | Value (${my_associative_array[$element_key]}) from array element (${element_key}) does not match provided element value (${element_value})." 1>&2
    return 2
  else
    echo -e "\n[INFO] ${FUNCNAME[0]} | Value (${my_associative_array[$element_key]}) from array element (${element_key}) does match provided element value (${element_value})."
    return 0
  fi

}

Test

This is the original contents of the test file (../labs/03-arrays/03-arrays.test.sh).

Review the test cases and your lab file.

Will the lab file (../labs/03-arrays/03-arrays.lab.sh) pass all test cases?

#!/usr/bin/env bash

test_assert_indexed_array_element_contains_value() {

   ../build/sobash assert-index-array-element-contains-value LAB03A_INDEXED_ARRAY LAB03A_INDEX_NUMBER LAB03A_INDEX_VALUE
   assertEquals 0 $?

}

test_assert_associative_array_element_contains_value() {

   ../build/sobash assert-associative-array-element-contains-value LAB03B_ASSOCIATIVE_ARRAY LAB03B_ELEMENT_KEY LAB03B_ELEMENT_VALUE
   assertEquals 0 $?

}

source ./shunit2

When ready, run the following to execute the tests above against the lab file:

cd "${HOME}/bash-programming/src/" \ 
  && ./test.sh lab 03-arrays

Solution

This is the original contents of the solution file (../labs/03-arrays/03-arrays.solution.sh).

This file contains an example of a viable solution that passes all the test cases.

# Assume "LAB03A_INDEXED_ARRAY" is passed as the "$1" positional parameter
LAB03A_INDEXED_ARRAY=( "zero" "one" "two" "three" )
LAB03A_INDEXED_ARRAY+=( "four" )
LAB03A_INDEXED_ARRAY[6]="six"
LAB03A_INDEXED_ARRAY+=( "mystery" )
export LAB03A_INDEXED_ARRAY

# Assume "LAB03A_INDEX_NUMBER" is passed as the "$2" positional parameter
LAB03A_INDEX_NUMBER="7"
export LAB03A_INDEX_NUMBER

# Assume "LAB03A_INDEX_VALUE" is passed as the "$3" positional parameter
LAB03A_INDEX_VALUE="mystery"
export LAB03A_INDEX_VALUE

sobash_assert_index_array_element_contains_value() {

  local -n my_indexed_array
  local -n index_number
  local -n index_value

  my_indexed_array="$1"
  index_number="$2"
  index_value="$3"

  if [[ "$#" == "0" ]]; then
    echo -e "\n[FAIL] ${FUNCNAME[0]} | Failed to pass arguments to function."
    return 1
  fi

  if [[ "${my_indexed_array[$index_number]}" != "${index_value}" ]]; then
    echo -e "\n[FAIL] ${FUNCNAME[0]} | Value (${my_indexed_array[$index_number]}) from array element (${index_number}) does not match provided index value (${index_value})." 1>&2
    return 2
  else
    echo -e "\n[INFO] ${FUNCNAME[0]} | Value (${my_indexed_array[$index_number]}) from array element (${index_number}) does match provided index value (${index_value})."
    return 0
  fi

}

# Assume "LAB03_ASSOCIATIVE_ARRAY" is passed as the "$1" positional parameter
declare -A LAB03B_ASSOCIATIVE_ARRAY
LAB03B_ASSOCIATIVE_ARRAY=( [zero]="zero" [one]="one" [two]="two" [three]="three" )
LAB03B_ASSOCIATIVE_ARRAY+=( [four]="four" )
LAB03B_ASSOCIATIVE_ARRAY[six]="six"

# shellcheck disable=SC2190
LAB03B_ASSOCIATIVE_ARRAY+=( "seven" )
export LAB03B_ASSOCIATIVE_ARRAY

# Assume "LAB0B_ELEMENT_KEY" is passed as the "$2" positional parameter
LAB03B_ELEMENT_KEY="seven"
export LAB03B_ELEMENT_KEY

# Assume "LAB03A_ELEMENT_VALUE" is passed as the "$3" positional parameter
LAB03B_ELEMENT_VALUE=""
export LAB03B_ELEMENT_VALUE

sobash_assert_associative_array_element_contains_value() {

  local -n my_associative_array
  local -n element_key
  local -n element_value

  my_associative_array="$1"
  element_key="$2"
  element_value="$3"

  if [[ "$#" == "0" ]]; then
    echo -e "\n[FAIL] ${FUNCNAME[0]} | Failed to pass arguments to function."
    return 1
  fi

  if [[ "${my_associative_array[$element_key]}" != "${element_value}" ]]; then
    echo -e "\n[FAIL] ${FUNCNAME[0]} | Value (${my_associative_array[$element_key]}) from array element (${element_key}) does not match provided element value (${element_value})." 1>&2
    return 2
  else
    echo -e "\n[INFO] ${FUNCNAME[0]} | Value (${my_associative_array[$element_key]}) from array element (${element_key}) does match provided element value (${element_value})."
    return 0
  fi

}

Run the following to execute the tests above against the solution file:

cd "${HOME}/bash-programming/src/" \ 
  && ./test.sh solution 03-arrays

Feel free to run the following to override the contents of the lab file with the solution file.

cd "${HOME}/bash-programming/labs/" \ 
  && cp ./03-arrays/03-arrays.{solution,lab}.sh