PHP试题

判断一个数组里有没有重复的值

if (count($array) != count(array_unique($array))) {   
   echo '该数组有重复值';  
} 

统计出两个数组(长度10000)中同时出现过的，并且总出现次数最多的单词

$arr1 = array(1, "hello", 1, "world", "hello",2,2);
$arr2 = array(1, "hello", 11, "world1", "hello1",2,2);
$arr_count1=array_count_values($arr1);
$arr_count2=array_count_values($arr2);
$arr=array_intersect($arr1,$arr2);

$arr_result=array();
foreach ($arr as $v){
    $arr_result[$v]=$arr_count1[$v]+$arr_count2[$v];
}

asort($arr_result);
var_dump($arr_result);

找出数组中不重复出现的值

$all = '1,2,3,4,5,6';
$in = '2,3,4';

$str = $all.','.$in;

$arr = explode(',', $str);

// 计算数组中每个值出现的次数
$arr = array_count_values($arr);

    foreach ($arr as $key => $value) {
        if($value == 1){
            $left[] = $key;
        }
    }

print_r($left);

array_search与array_column实现二维数组查找

$userdb = array(
    0 => array(
            'uid' => 100,
            'name' => 'Sandra Shush',
            'url' => 'urlof100'
        ),
 
    1 => array(
            'uid' => 5465,
            'name' => 'Stefanie Mcmohn',
            'pic_square' => 'urlof100'
        ),
 
    2 => Array(
            'uid' => 40489,
            'name' => 'Michael',
            'pic_square' => 'urlof40489'
        )
);
 
$found_key = array_search(40489, array_column($userdb, 'uid'));
/**
    如果$userdb很大，建议使用一个变量，避免搜索每个元素时都调用array_column()
    $uid = array_column($userdb, 'uid');
    $found_key = array_search(40489, $uid);
 */

var_dump($found_key);