Tutorial

Arithmetic Operators

Simple arithmetics on variables can be done using the arithmetic expression: $((expression))

A=3
B=$((100 * $A + 5)) # 305

The basic operators are:

a + b addition (a plus b)

a - b substraction (a minus b)

a * b multiplication (a times b)

a / b division (integer) (a divided by b)

a % b modulo (the integer remainder of a divided by b)

a ** b exponentiation (a to the power of b)

Exercise

In this exercise, you will need to calculate to total cost (variable TOTAL) of a fruit basket, which contains 1 pineapple, 2 bananas and 3 watermelons. Don’t forget to include the cost of the basket….

Tutorial Code

#!/bin/bash
COST_PINEAPPLE=50
COST_BANANA=4
COST_WATERMELON=23
COST_BASKET=1
TOTAL=
echo "Total Cost is $TOTAL"

Expected Output

Total Cost is 128

Show Solution

#!/bin/bash
COST_PINEAPPLE=50
COST_BANANA=4
COST_WATERMELON=23
COST_BASKET=1
TOTAL=$(($COST_PINEAPPLE + $COST_BANANA + $COST_WATERMELON + $COST_BASKET))
echo "Total Cost is $TOTAL"