How do I echo a sum of a variable and a number?

Question

I have a variable x=7 and I want to echo it plus one, like echo ($x+1) but I\'m getting:

bash: syntax error near unexpected

Answer 1

You can also use the bc utility:

$ x=3;
$ echo "$x+5.5" | bc
8.5

Answer 2

Try this way:

echo $(( $X + 1 ))

Answer 3

We use expr for that:

echo `expr $x + 1`