#!/bin/bash

echo

let a=11            # Same as 'a=11'
let a=a+5           # Equivalent to  let "a = a + 5"
                    # (Double quotes and spaces make it more readable.)
echo "11 + 5 = $a"  # 16

let "a <<= 3"       # Equivalent to  let "a = a << 3"
echo "\"\$a\" (=16) left-shifted 3 places = $a"
                    # 128

let "a /= 4"        # Equivalent to  let "a = a / 4"
echo "128 / 4 = $a" # 32

let "a -= 5"        # Equivalent to  let "a = a - 5"
echo "32 - 5 = $a"  # 27

let "a *=  10"      # Equivalent to  let "a = a * 10"
echo "27 * 10 = $a" # 270

let "a %= 8"        # Equivalent to  let "a = a % 8"
echo "270 modulo 8 = $a  (270 / 8 = 33, remainder $a)"
                    # 6


# Does "let" permit C-style operators?
# Yes, just as the (( ... )) double-parentheses construct does.

let a++             # C-style (post) increment.
echo "6++ = $a"     # 6++ = 7
let a--             # C-style decrement.
echo "7-- = $a"     # 7-- = 6
# Of course, ++a, etc., also allowed . . .
echo


# Trinary operator.

# Note that $a is 6, see above.
let "t = a<7?7:11"   # True
echo $t  # 7

let a++
let "t = a<7?7:11"   # False
echo $t  #     11

exit