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+====== Arrays ======
+**Concepts:**\\
+Bash //arrays// and //associative arrays//.
+**Text:**\\
+Write an example that illustrates the use of bash //arrays// and //associative arrays//.\\
+In bash //array//, the index of the array must be an integer number. Some gaps may be present, i.e., indices can be not continuous.\\
+Instead, bash //associative arrays// are like hash maps, and the index of the array must be a string.
+**Solution:**\\
+<code bash arrays.sh>
+#!/bin/bash
+# Example of use of the BASH arrays (and associative arrays)
+# Classical array
+echo "Classical array"
+vett2[3]=pasta
+vett2[6]=bread
+echo ${vett2[3]}  # Prints pasta
+echo ${#vett2[*]} # Prints 2
+echo ${vett2[*]}  # Prints bread pasta
+echo ${!vett2[*]} # Prints 3 6
+# Associative array
+echo -e "\nAssociative array"
+declare -A vett1
+vett1[stefano]=3
+nome=giulia
+vett1[$nome]=pippo
+echo ${vett1[stefano]}  # Prints 3
+echo ${vett1["giulia"]} # Prints pippo
+echo ${#vett1[*]}       # Prints 2
+echo ${vett1[*]}        # Prints pippo 3
+echo ${!vett1[*]}       # Prints giulia stefano
+sum=0
+for name in ${!vett1[*]}
+do
+    let sum=${vett1[$name]}+$sum
+done
+echo "Sum: $sum"
+unset vett1
+echo ${#vett1[*]} # Prints 0 (because vett1 does not exist)
+</code>
+**Output:**\\
+<code bash>
+$ ./arrays.sh
+Classical array
+pasta
+pasta bread
+6
+Associative array
+pippo
+pippo 3
+giulia stefano
+Sum: 3
+</code>

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