erlang精要(14)－列表（1）

1> X=[1,2,3].
[1,2,3]
2> Y=[4,5,6].
[4,5,6]
5> [X|Y].
[[1,2,3],4,5,6]
7> [Fst|Rest]=Y.
[4,5,6]
8> Fst.
4
9> Rest.
[5,6]
10> [One,Two,Three]=X.
[1,2,3]
11> One.
1
12> Three.
3
13> 

奇数和偶数的判断

116> learnerl:loop([1,2,3]). 
1 是奇数
2 是偶数
3 是奇数
byebye.
ok
117> 

-module(learnerl).
-export([loop/1]).


is_odd(Num)->
     Rn=Num rem 2,
     case Rn of
         1->io:format("~p 是奇数~n",[Num]);
         0->io:format("~p 是偶数~n",[Num])
     end.
     
     

loop([Fst|Rst])->
    is_odd(Fst),
    loop(Rst);  
loop([]) ->io:format("byebye.~n").

所有奇数的和

-module(learnerl).
-export([total/3]).


is_odd(Num)->
     Rn=Num rem 2,
     case Rn of
         1->true;
         0->false
     end.
     
output_lst([Fst|Rst])->
    io:format("~p,",[Fst]),
    output_lst(Rst);
output_lst([]) ->io:format("~n").

total([Fst|Rst],OddLst,Sum)->
    case is_odd(Fst) of
        true->NewSum=Sum+Fst,NewOddLst=[Fst|OddLst];
        false->NewSum=Sum,NewOddLst=OddLst
    end,
    total(Rst,NewOddLst,NewSum);
total([],OddLst,Sum) ->
    output_lst(OddLst), 
    OddLst,io:format("Sum=~p byebye.~n",[Sum]).

111> c(learnerl).
{ok,learnerl}
112> learnerl:total([1,2,3],[],0).         
3,1,
Sum=4 byebye.
ok
113>

标签：14,format,Sum,Fst,io,Rst,精要,erlang,learnerl
来源： https://blog.csdn.net/AI_LX/article/details/113801242