Question

我正在尝试生成随机字符。我使用foreach循环连接 $ char_type 的值，但它没有显示任何内容。这是我的代码：

  TMyDataAwareComponent = class(TDataAwareComponent)
  private
    { Private declarations }
    procedure ToBeExecutedOnAfterOpen(DataSet: TDataSet);
  protected
    { Protected declarations }
  public
    { Public declarations }
    constructor Create(AOwner: TComponent); override;
  end;

 constructor TMyDataAwareComponent.Create(AOwner: TComponent);
 begin
  inherited;
  if Assigned(Self.DataSource) then
  begin
    Self.DataSource.DataSet.AfterOpen := ToBeExecutedOnAfterOpen;
  end;
 end;

 procedure TMyDataAwareComponent.ToBeExecutedOnAfterOpen(DataSet: TDataSet);
 var
  i: Integer;
 begin
    // Do something here
 end;

更新我想从public function randomizer($range, $type) { $strtester = ''; $char_type = array('alp_sm' => 'abcdefghijklmnopqrstuvwxyz', 'alp_cs' => 'ABCDEFGHIJKLMNOPQRSTUVWXYZ', 'num' => '0123456789', 'sp' => '!@#$%^&*()'); if(is_array($type)) { foreach($type as $row) { if(in_array($row, $char_type)) { $strtester .= $char_type[$row]; } } } print_r($strtester); exit(); $seed = str_split($strtester); shuffle($seed); $generated_string = ''; foreach (array_rand($seed, $range) as $k) $generated_string .= $seed[$k]; return $generated_string; }得到的是例如我想要$strtester alp_sm 和 alp_cs 然后$char_type将获得{{1} }}

提前谢谢

Answer 1

将if(in_array($row, $char_type)) {替换为if(array_key_exists($row, $char_type)) {，然后尝试

    function randomizer($range, $type) {
         $strtester = '';
         $char_type = array('alp_sm' => 'abcdefghijklmnopqrstuvwxyz',
                            'alp_cs' => 'ABCDEFGHIJKLMNOPQRSTUVWXYZ',
                            'num'    => '0123456789',
                            'sp'     => '!@#$%^&*()');

        if(is_array($type)) {
            foreach($type as $row) {
                if(array_key_exists($row, $char_type)) {
                    $strtester .= $char_type[$row];
                }
            }
        }

        $seed = str_split($strtester);
        shuffle($seed);
        $generated_string = '';
        foreach (array_rand($seed, $range) as $k) 
            $generated_string .= $seed[$k];
        return $generated_string;
    }

    $res =  randomizer(5, array("alp_sm"));
    print_r($res);

Answer 2

错误在于：

if(in_array($row, $char_type)) {

您实际上是在查找密钥是否存在，而不是数组是否包含该字符串 - 您需要使用isset：

if(is_array($type)) {
    foreach($type as $row) {
        if(isset($char_type[$row]) {
            $strtester .= $char_type[$row];
        }
    }
}
print_r($strtester); exit();

Answer 3

我不确定这一点，但我认为这可能是最容易解决的问题

function randomizer($range, $type) {
     $char_type = array('alp_sm' => range('a','z'),
                        'alp_cs' => range('A','Z'),
                        'num'    => range(0,9),
                        'sp'     => ['!','@','#','$','%','^','&','*','(',')']);
    shuffle($char_type[$type[0]]);                    
    $generated_string = implode(array_slice($char_type[$type[0]],0,$range));
    return $generated_string;
}

$res =  randomizer(5, array("alp_sm"));
print_r($res);

Answer 4

您必须检查is_array。它检查变量是否为数组

$strtester = '';
if(is_array($type)) {
    foreach($type as $row) {
        if(isset($char_type[$row]) {
            $strtester .= $char_type[$row];
        }
    }
}

参考PHP Docs for is_array

使用foreach连接字符串

4 个答案: