Question

请问您可以告知如何检查其中一个表单输入字段在php中是否为空，无论输入字段名称是什么。

8> pi:pi(5).
{314159,1231847548,392109375}
9> 1231847548/392109375.
3.141591674516836
10> pi:pi(16).           
{31415926535897932,1954593375063141623418966719395892212,
 622166394751939884889125823974609375}
11> 1954593375063141623418966719395892212/622166394751939884889125823974609375.
3.141592653589793
12> pi:pi(100).                                                                
{31415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679,
 76687493427849560932551539133547355657552111418520642454352142367859087475777099790110509028596728165604330274537401085479755361074012954953620747810364589561632946227768531437131849315704805073879011158859557501594908388272923613955511642353579477204804,
 24410387304738988881243138674543333937873180956639377144249334863653319012629901313275720024646578388088082064861007931480541676642001787010751232779539604168044020067382957776693277819044947249055510862819577525863190547994463486247695982456207275390625}

-module (pi).

-export ([arctan/2,pi/1,pgcd/2,cf/2,fra/2]).

%% @doc
%% arctan({N:integer(),D:integer()},P:integer()) -> {N1:integer(),D1:integer()}
%% evaluate the value of arctan(N/D) with a precision of P digits
%% return the result as a fraction N1/D1
arctan({N,D},P) ->
    N2=N*N,
    D2=D*D,
    arctan([{N,D}],N2,D2,-1,3,N2*N,D2*D,P).

%% @doc
%% L is the list of {D,N} terms of the result,
%% N2 and D2 are the square values of initial N,D
%% S is the sign of the next term
%% 1/F is the coefficient of the next term of the serie
%% Nc/Dc is the next power of the initial N/D number
%% P the precision
arctan(L,_N2,_D2,_S,F,Nc,Dc,P) when P*Nc < F*Dc ->
    sumterm(L);
arctan(L,N2,D2,S,F,Nc,Dc,P) ->
    arctan([{S*Nc,F*Dc}|L],N2,D2,-S,F+2,Nc*N2,Dc*D2,P).

sumterm(L) ->
    D = lists:foldl(fun({_,X},A) -> X*A end,1,L),
    N =lists:foldl(fun({X,Y},A) -> X * D div Y + A end,0,L),
    {N,D}.

pi(P) ->
    P1 = list_to_integer(lists:reverse(string:chars($0,P,"1"))),
    {N1,D1} = arctan({1,5},32*P1),
    {N2,D2} = arctan({1,239},8*P1),
    N3 = 16*N1*D2 - 4*N2*D1,
    D3 = D1*D2,
    P3 = pgcd(D3,N3),
    N4 = N3 div P3,
    D4 = D3 div P3,
    {(N4*P1) div D4, N4, D4}.

-spec pgcd(non_neg_integer(),non_neg_integer()) -> non_neg_integer().
%% @doc Compute the greatest common divider of A and B
pgcd(A,B) when is_integer(A), is_integer(B), A >= 0, B >= 0 ->
    gcd(A,B).

-spec gcd(non_neg_integer(),non_neg_integer()) -> non_neg_integer().
gcd(A, B) when A < B -> gcd(B, A);
gcd(A, 0) -> A;
gcd(A, B) -> gcd(B, A rem B).


cf(P,Q) -> cf(P,Q,[]).

cf(P,1,L) -> lists:reverse([P|L]);
cf(P,Q,L) ->
    P1 = P div Q,
    Q1 = P rem Q,
    cf(Q,Q1,[P1|L]).

fra(L,N) ->
    N1 = min(length(L),N) -1,
    L1 = lists:sublist(L,N1),
    P = lists:nth(N1+1,L),
    fra(P,1,lists:reverse(L1)).

fra(N,D,[]) -> {N,D};
fra(N,D,[H|T]) -> fra(N*H+D,N,T).

但是，请不要告诉我以下代码。

<form name="form1" method="POST">
<input type="text" name="a">
<input type="text" name="b">
</form>

Answer 1

循环通过POST数组并像这样测试值

if( $_SERVER['REQUEST_METHOD']=='POST' ){
    foreach( $_POST as $field => $value ){
        if( !empty($value) ){
            exit( $field . 'is NOT empty' );
        }
    }
}

Answer 2

如果有多个输入字段，if语句可能会很长。

您应该在POST数据上使用array_filter()功能。

试试这个：

 if (array_filter($_POST)) {
    echo "Proceed";
 } else {
    echo "One of the fields is blank";
 }

检查其中一个表单输入字段在php中不为空

2 个答案: