#!/bin/bash# int-or-string.sh: 整型還是字符串?a=2334                   # 整型.let "a += 1"echo "a = $a "           # a = 2335echo                     # 還是整型.b=${a/23/BB}             # 將"23"替換成"BB".                         # 這將把變量b從整型變為字符串.echo "b = $b"            # b = BB35declare -i b             # 即使使用declare命令也不會對此有任何幫助.echo "b = $b"            # b = BB35let "b += 1"             # BB35 + 1 =echo "b = $b"            # b = 1echoc=BB34echo "c = $c"            # c = BB34d=${c/BB/23}             # 將"BB"替換成"23".                         # 這使得變量$d變為一個整形.echo "d = $d"            # d = 2334let "d += 1"             # 2334 + 1 =echo "d = $d"            # d = 2335echo# null變量會如何呢?e=""echo "e = $e"            # e =let "e += 1"             # 算術操作允許一個null變量?echo "e = $e"            # e = 1echo                     # null變量將被轉換成一個整型變量.# 如果沒有聲明變量會怎樣?echo "f = $f"            # f =let "f += 1"             # 算術操作能通過么?echo "f = $f"            # f = 1echo                     # 未聲明的變量將轉換成一個整型變量.# 所以說Bash中的變量都是不區分類型的.exit 0