Operations in the Arithmetic Expressions

The operations in arithmetic expression

The following table shows the operations we can perform in arithmetic expressions.

Operation	Description	Example
	Calculations
*	Multiplication	echo "$((2 * 9)) = 18"
/	Division	echo "$((25 / 5)) = 5"
%	The remainder of division	echo "$((8 % 3)) = 2"
+	Addition	echo "$((7 + 3)) = 10"
-	Subtraction	echo "$((8 - 5)) = 3"
**	Exponentiation	echo "$((4**3)) = 64"
	Bitwise operations
~	Bitwise NOT	echo "$((~5)) = -6"
<<	Bitwise left shift	echo "$((5 << 1)) = 10"
>>	Bitwise right shift	echo "$((5 >> 1)) = 2"
&	Bitwise AND	echo "$((5 & 4)) = 4"
|	Bitwise OR	echo "$((5 | 2)) = 7"
^	Bitwise XOR	echo "$((5 ^ 4)) = 1"
	Assignments
=	Ordinary assignment	echo "$((num = 5)) = 5"
*=	Multiply and assign the result	echo "$((num *= 2)) = 10"
/=	Divide and assign the result	echo "$((num /= 2)) = 5"
%=	Get the remainder of the division and assign it	echo "$((num %= 2)) = 1"
+=	Add and assign the result	echo "$((num += 7)) = 8"
-=	Subtract and assign the result	echo "$((num -= 3)) = 5"
<<=	Do bitwise left shift and assign the result	echo "$((num <<= 1)) = 10
>>=	Do bitwise right shift and assign the result	echo "$((num >>= 2)) = 2"
&=	Do bitwise AND and assign the result	echo "$((num &= 3)) = 2"
^=	Do bitwise XOR and assign the result	echo "$((num^=7)) = 5"
|=	Do bitwise OR and assign the result	echo "$((num |= 7)) = 7"
	Comparisons
<	Less than	((num < 5)) && echo "The \"num\" variable is less than 5"
>	Greater than	((num > 5)) && echo "The \"num\" variable is greater than 3"
<=	Less than or equal	((num <= 20)) && echo "The \"num\" variable is less or equal 20"
>=	Greater than or equal	((num >= 15)) && echo "The \"num\" variable is greater or equal 15"
==	Equal	((num == 3)) && echo "The \"num\" variable is equal to 3"
!=	Not equal	((num != 3)) && echo "The \"num\" variable is not equal to 3"
	Logical operations
!	Logical NOT	(( ! num )) && echo "The \"num\" variable is FALSE"
&&	Logical AND	(( 3 < num && num < 5 )) && echo "The \"num\" variable is greater than 3 but less than 5"
||	Logical OR	(( num < 3 || 5 < num )) && echo "The \"num\" variable is less than 3 or greater than 5"
	Other operations
num++	Postfix increment	echo "$((num++))"
num--	Postfix decrement	echo "$((num--))"
++num	Prefix increment	echo "$((++num))"
--num	Prefix decrement	echo "$((--num))"
+num	Unary plus or multiplication of a number by 1	a=$((+num))"
-num	Unary minus or multiplication of a number by -1	a=$((-num))"
CONDITION ? ACTION_1 : ACTION_2	Ternary operator	a=$(( b < c ? b : c ))
ACTION_1, ACTION_2	The list of expressions	((a = 4 + 5, b = 16 - 7))
( ACTION_1 )	Grouping of expressions (subexpression)	a=$(( (4 + 5) * 2 ))

Bash performs all operations in the arithmetic expression in order of their priorities. The operations with a higher priority come first.

Run the commands discussed in this lesson in the terminal below.