Which of the following commands puts the output of the command date into the shell variable mydate?

Question

Options

• Amydate="date"
• Bmydate="exec date"
• Cmydate="$((date))"
• Dmydate="$(date)"
• Emydate="${date}"

• A
  4% (2)
• B
  2% (1)
• C
  11% (6)
• D
  82% (47)
• E
  2% (1)

Explanation

Option D uses command substitution - the $(...) syntax tells the shell to execute the command inside and replace the expression with its output, so mydate="$(date)" runs date and stores its output in mydate.

Why the others fail:

• A assigns the literal string "date" - no execution happens.
• B assigns the literal string "exec date" - exec is a shell builtin, but wrapping it in quotes just makes it a string.
• C uses $((...)) which is arithmetic expansion, not command substitution - it evaluates math expressions, not commands.
• E uses ${date} which is variable expansion - it reads the value of a variable named date, not the date command.

Memory tip: Think of $( ) as "run this and give me the result" - the parentheses are like a container that executes, while quotes store literally and ${ } reads a variable. If you want a command's output, you need the command substitution form: $(command).

No community discussion yet for this question.