Bash WTF?

# Standard command substitution
echo $(ls)

# Backtick variant (older and not recommended)
echo `ls`

echo {a,b,c}

# Compare directory contents
diff <(ls dir1) <(ls dir2)

# Example with a command
grep foo <(echo foo)

# Example with a file
grep foo <(cat file)

# Input redirection
echo "foo" > >(cat)

#!/bin/bash

# Declare an associative array
declare -A fruits

# Add key-value pairs
fruits[apple]="green"
fruits[banana]="yellow"
fruits[cherry]="red"

# Access and print values
echo "The color of an apple is ${fruits[apple]}"
echo "The color of a banana is ${fruits[banana]}"
echo "The color of a cherry is ${fruits[cherry]}"

# Iterate over keys and values
for fruit in "${!fruits[@]}"; do
    echo "$fruit is ${fruits[$fruit]}"
done

# Declare an indexed array
arr=(a b c)

# Access elements
echo "First element: ${arr[0]}"
echo "Second element: ${arr[1]}"
echo "Third element: ${arr[2]}"

# Iterate over elements
for element in "${arr[@]}"; do
    echo "Element: $element"
done

cat <<EOF
This is a here document.
It will continue until it sees EOF.
EOF

while read -r id; do
  # some commands using $id
done <<< "$ids"

{ echo hi; echo there; } > test.txt