腾讯php社招面试题_腾讯PHP面试题

1.setcookie('a','value');print $_COOKIE['a'];输出结果是啥?

答:value  第一次访问为空!第二次访问$_COOKIE['a']已经被赋值完成!

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2.

try {

require_once "aaa";

print "aaa";

} catch (Exception $e) {

echo 'dddd';

}

结果是啥?

答:没有输出。程序退出。

如果修改为:

try {

include_once "aaa";

print "aaa";

} catch (Exception $e) {

echo 'dddd';

}

则输出aaa

或者修改为:

try {

if(!include_once "aaa") {

throw new Exception;

}

print "aaa";

} catch (Exception $e) {

echo 'dddd';

}

则输出dddd

本人测试,原题的代码输出就是aaa 或者aaa文件不存在时报警告信息

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3.

用JS实现trim函数

答:虽然javascript中没有trim()函数,但是可以使用正则表达式实现trim()函数的功能。

String.prototype.trim = function() {

var reg = /^\s*(.*?)\s*$/;

return this.replace(reg,"$1");

}

function Testtrim() {

var TestStr = " yingfm ";

alert("("+TestStr.trim()+")");

}

Testtrim();

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4.

输出啥?

答:本人觉得应该输出1.js中输出的内容

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5.

输出啥?

答:e       经测试,确实输出e,看看alert(["a","b","c","d","e"][4,3,2])的输出是什么

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6.

类似这样的aaasssddd字符串,写个函数CutStr($str,$max)实现截取:

1)如果$max大于$str的长度则返回$str

2)不包含在长度计算范围。

例:

如果CutStr("aaasssddd",6) 则返回aaasss.

如果CutStr("aaasssddd",4) 则返回aaas,不包含标签

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7.

不使用php内置函数实现数组排序,如果value相等,比较key的值。例: array("d" => 100,"c" => 22, "a" => 22);

答:

简单排序:

$data = array(5,8,1,7,2);

sort($data);//从低到高排序

print_r($data);

rsort($data);//从高到低排序

?>

输出:

Array ( [0] => 1 [1] => 2 [2] => 5 [3] => 7 [4] => 8 )

Array ( [0] => 8 [1] => 7 [2] => 5 [3] => 2 [4] => 1 )

根据关键字排序:

$data = array("US"=>"United States","IN"=>"India","DE"=>"Germany","ES"=>

"Spain");

ksort($data);//它的相反排序函数krsort()

print_r($data);

?>

输出:

Array ( [DE] => Germany [ES] => Spain [IN] => India [US] => United States )

根据值排序:使用asort()代替ksort()就可以。它的相反排序arsort()

Array ( [DE] => Germany [IN] => India [ES] => Spain [US] => United States )

自然语言排序: natsort(),对它的相反操作可以使用array_reverse()

$data = array("book-1","book-10","book-100","book-5");

sort($data);

print_r($data);

natsort($data);

print_r($data);

?>

输出结果:

Array ( [0] => book-1 [1] => book-10 [2] => book-100 [3] => book-5 )

Array ( [0] => book-1 [3] => book-5 [1] => book-10 [2] => book-100 )

根据用户自己定义的规则排序:

function sortByLen($a, $b) {

if (strlen($a) == strlen($b)) {

return 0;

} else {

return (strlen($a) > strlen($b)) ? 1 : -1;

}

}

$data = array("joe@", "@", "asmithsonian@", "jay@");

usort($data, 'sortByLen');

print_r($data);

?>

多维排序:

$data = array(array("id" => 1, "name" => "Boney M", "rating" => 3),

array("id" => 2, "name" => "Take That", "rating" => 1),

array("id" => 3, "name" => "The Killers", "rating" => 4),

array("id" => 4, "name" => "Lusain", "rating" => 3)

);

foreach ($data as $key => $value) {

$name[$key] = $value['name'];

$rating[$key] = $value['rating'];

}

array_multisort($rating, $name, $data);

print_r($data);

?>

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8.

数据库中有两个字段 id, sorce.假设sorce的取值范围是 5-10.

按照以下概率实现sorce数据的更新。

5(25%) => 6 5(25%) => 7

6(20%) => 7

7(25%) => 8 7(25%) => 6

8(10%) => 6 8(25%) => 9

9(15%) => 8 9(20%) => 10

10(25%) => 9

要求考虑性能及扩展性。写出概率分布相关代码。

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9.

设计一个缓存系统。写出思路。画出图。考虑命中,生存期等多种要素。

答:可以参考memcached

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