有个这样的例子：list里面是多个个tuple—list 或者maps，

ListA = [[{},{}}],[{},{}]], 举例：

A = [[{<<"CARDISSUERID">>,<<"2">>},
{<<"CARDSTOCKTYPE">>,1},
{<<"CARDTYPE">>,0},
{<<"DERIVATIVESPRODUCTTYPE">>,1},
{<<"PARAM_VER">>,<<"195">>},
{<<"PREASSIGNMENTATTRIBUTE">>,1},
{<<"PRODUCTTYPE">>,9800},
{<<"SALEVALUE">>,<<"0">>}],
[{<<"CARDISSUERID">>,<<"2">>},
{<<"CARDSTOCKTYPE">>,1},
{<<"CARDTYPE">>,0},
{<<"DERIVATIVESPRODUCTTYPE">>,1},
{<<"PARAM_VER">>,<<"195">>},
{<<"PREASSIGNMENTATTRIBUTE">>,1},
{<<"PRODUCTTYPE">>,9800},
{<<"SALEVALUE">>,<<"0">>}]].

 

　　想把  key是 <<"CARDISSUERID">> 的 值的类型，改成integer ，目前是 binary ，{<<"CARDISSUERID">>,<<"2">>}

直接上代码，修改对应key的值，直接干：

[lists:map(fun(X) -> if element(1,X) == <<"CARDISSUERID">> -> 
                                     {element(1,X), binary_to_integer(element(2,X))};
                            true -> X
                     end 
                end,Z)|| Z<-A].

 

　执行结果如下：