面试题02

#关于字符串的测试
 //$v = '00';
// $x2 = $v+1;
 //echo $v&1;
 //echo($v == 1)?'相等':'不相等';
 //结论：对于字符串的以0开头后面接数字的 在进行运算(算术、逻辑、判断相等)时都会先转化成数值型
 #关于数组的测试
 /*$i = '01';
 $arr = array(1,2);
 if(array_key_exists($i,$arr)){
    echo 'exist';
 }else{
  echo 'not exist';
 }
$id = "22";  $arr1[$id] = "xxx";  var_dump($arr1);  
$id = 22;  $arr2[$id] = "xxx";  var_dump($arr2);  
$id = "022";  $arr3[$id] = "xxx";  var_dump($arr3);  
$id = "2222222222222";  $arr4[$id] = "xxx";  var_dump($arr4);*/ 
 //结论：key 能够是 integer 或者 string。若是key是一个 integer 的标准表示，则被解释为整数（例如 "8" 将被解释为 8，而 "08" 将被解释为 "08"）。key 中的浮点数被取整为 integer。
 #用于匹配html文件里的<img/>
 /*$imgstr =     '<img class="home-thumb" src="http://www.daixiaorui.com/Public/images/random/20.jpg" width="140px" height="100px" alt="php源码，小程序"/>
    <p><img src="http://www.daixiaorui.com/Public/uploads/20130727/chat2.jpg" style="border:1px solid #aaa;" alt="PHP+Ajax"/>
    <img  src=\'http://www.daixiaorui.com/Public/images/random/20.jpg\' width="140px" height="100px" alt="php源码，小程序"/></p>
    <img src=http://www.daixiaorui.com/Public/images/random/20.jpg />';
 $regexp = '/<img\s+([^>]+)(\/>)/i';
 preg_match_all($regexp,$imgstr,$res);
 echo '<pre>';
 print_r($res);
 echo '</pre>';*/
 #用于匹配html文件里的<img/>的src的地址
 /*$imgstr =     '<img class="home-thumb" src="http://www.daixiaorui.com/Public/images/random/20.jpg" width="140px" height="100px" alt="php源码，小程序"/>
    <p><img src="http://www.daixiaorui.com/Public/uploads/20130727/chat2.jpg" style="border:1px solid #aaa;" alt="PHP+Ajax"/>
    <img  src=\'http://www.daixiaorui.com/Public/images/random/20.jpg\' width="140px" height="100px" alt="php源码，小程序"/></p>
    <img SRC=http://www.daixiaorui.com/Public/images/random/20.jpg />';
 $preg = '/(src|SRC)=(\"|\')?([^>]|[^\/>])+(\"|\')?/i';
 preg_match_all($preg,$imgstr,$res);
 echo '<pre>';
 print_r($res);
 echo '</pre>';
  $str = 'asdsadsadsad撒大声地';
 $preg= '/[\x{4e00}-\x{9fa5}]+/u';
 preg_match($preg,$str,$res);
 echo '<pre>';
 print_r($res);
 echo '</pre>';*/
#php打印前一天的时间格式是  Y-m-d H:i:s
//print(date('Y-m-d H:i:s',time()-3600*24));
//print(date('Y-m-d H:i:s',strtotime('-1 day')));
#求两个日期的差数，例如2011-2-5 ~ 2011 -3-6
// 方法一echo round(abs(strtotime('2011-3-6')- strtotime('2011-2-5'))/3600/24);
function date_cha($date1,$date2){
     $year1 = (int)substr($date1,0,4);
     $year2 = (int)substr($date2,0,4);
     //echo $year1,'---',$year2;
     $mon1 = (int)substr($date1,strpos($date1,'-')+1,1);
     $mon2 = (int)substr($date2,strpos($date2,'-')+1,1);
     //echo $mon1;
     $day1 = (int)substr($date1,-1);
     $day2 = (int)substr($date2,-1);
     //echo $day1;
    is_run($year1)?$sum_1=nowday($mon1,$day1)+1:$sum_1=nowday($mon1,$day1);
    is_run($year2)?$sum_2=nowday($mon2,$day2)+1:$sum_2=nowday($mon2,$day2);
    //echo $sum_1;
    $res = abs($sum_1-$sum_2);
    return $res;
}
function is_run($year){//判断是不是闰年
    if((($year%4 == 0) && ($year%100 != 0)) || ($year %400 == 0)){
            return true;
    }else{
            return false;
    }
}
function nowday($mon,$day){//计算这是这一年的哪一天
    $sum = 0;
    switch($mon){
           case 1:$sum = 0;break;
           case 2:$sum = 31;break;
           case 3:$sum = 59;break;
           case 4:$sum = 90;break;
           case 5:$sum = 120;break;
           case 6:$sum = 151;break;
           case 7:$sum = 181;break;
           case 8:$sum = 212;break;
           case 9:$sum = 243;break;
           case 10:$sum = 273;break;
           case 11:$sum = 304;break;
           case 12:$sum = 324;break;
    }
    $sum += $day;
    return $sum;
}
echo date_cha('2011-3-6','2011-2-5');/*　　关于这个的第二个解法  我只解出了相同年的日期  */