我在第 6 行有一个正则表达式。我已经对其进行了测试，并确认它有效。现在，我有一个非常大的数组。虽然我已经在较小的数组上测试过正则表达式，但它似乎不适用于较大的数组！是什么赋予了？基本上，下面的脚本旨在删除包含不常见字符的数组条目。看看当你尝试两个数组时会发生什么——第一个成功地删除了奇数数组条目，但较大的一个没有！
见这里： http ://pastebin.com/raw.php?i=KpNZHbrv
$sentences_working = array(
'Egypt, officially the Arab Republic of Egypt, is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia.',
'Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world.',
'The English name Egypt was borrowed from Middle French Egypte, from Latin, from ancient Greek Aígyptos, from earlier Linear B a-ku-pi-ti-yo.',
'In later years, the dynasty became a British puppet.',
);
$sentences_notworking = unserialize(urldecode("a%3A30%3A%7Bi%3A0%3Bs%3A160%3A%22Egypt++%2C+officially+the+Arab+Republic+of+Egypt%2C+Arabic%3A+%2C+is+a+country+mainly+in+North+Africa%2C+with+the+Sinai+Peninsula+forming+a+land+bridge+in+Southwest+Asia.%22%3Bi%3A1%3Bs%3A133%3A%22Egypt+is+thus+a+transcontinental+country%2C+and+a+major+power+in+Africa%2C+the+Mediterranean+Basin%2C+the+Middle+East+and+the+Muslim+world.%22%3Bi%3A2%3Bs%3A223%3A%22Covering+an+area+of+about+1%2C010%2C000+square+kilometers+%2C+Egypt+is+bordered+by+the+Mediterranean+Sea+to+the+north%2C+the+Gaza+Strip+and+Israel+to+the+northeast%2C+the+Red+Sea+to+the+east%2C+Sudan+to+the+south+and+Libya+to+the+west.%22%3Bi%3A3%3Bs%3A74%3A%22Egypt+is+one+of+the+most+populous+countries+in+Africa+and+the+Middle+East.%22%3Bi%3A4%3Bs%3A171%3A%22The+great+majority+of+its+over+81+million+people+live+near+the+banks+of+the+Nile+River%2C+in+an+area+of+about+40%2C000+square+kilometers+%2C+where+the+only+arable+land+is+found.%22%3Bi%3A5%3Bs%3A60%3A%22The+large+areas+of+the+Sahara+Desert+are+sparsely+inhabited.%22%3Bi%3A6%3Bs%3A177%3A%22About+half+of+Egypt%27s+residents+live+in+urban+areas%2C+with+most+spread+across+the+densely+populated+centres+of+greater+Cairo%2C+Alexandria+and+other+major+cities+in+the+Nile+Delta.%22%3Bi%3A7%3Bs%3A118%3A%22Monuments+in+Egypt+such+as+the+Giza+pyramid+complex+and+its+Great+Sphinx+were+constructed+by+its+ancient+civilization.%22%3Bi%3A8%3Bs%3A155%3A%22Its+ancient+ruins%2C+such+as+those+of+Memphis%2C+Thebes%2C+and+Karnak+and+the+Valley+of+the+Kings+outside+Luxor%2C+are+a+significant+focus+of+archaeological+study.%22%3Bi%3A9%3Bs%3A83%3A%22The+tourism+industry+and+the+Red+Sea+Riviera+employ+about+12%25+of+Egypt%27s+workforce.%22%3Bi%3A10%3Bs%3A170%3A%22The+economy+of+Egypt+is+one+of+the+most+diversified+in+the+Middle+East%2C+with+sectors+such+as+tourism%2C+agriculture%2C+industry+and+service+at+almost+equal+production+levels.%22%3Bi%3A11%3Bs%3A133%3A%22In+early+2011%2C+Egypt+underwent+a+revolution%2C+which+resulted+in+the+ousting+of+President+Hosni+Mubarak+after+nearly+30+years+in+power.%22%3Bi%3A12%3Bs%3A50%3A%22Presidential+elections+are+scheduled+for+May+2012.%22%3Bi%3A13%3Bs%3A190%3A%22The+English+name+Egypt+was+borrowed+from+Middle+French+Egypte%2C+from+Latin+%2C+from+ancient+Greek+A%26iacute%3Bgyptos+%2C+from+earlier+Linear+B+%26%2365601%3B%26%2365555%3B%26%2365568%3B%26%2365588%3B%26%2365549%3B+a-ku-pi-ti-yo.%22%3Bi%3A14%3Bs%3A277%3A%22The+adjective+aig%26yacute%3Bpti-%2C+aig%26yacute%3Bptios+was+borrowed+into+Coptic+as+%26%2311397%3B%26%2311433%3B%26%2311425%3B%26%231007%3B%26%2311411%3B%26%2311423%3B%26%2311429%3B%2F%26%2311413%3B%26%2311433%3B%26%2311425%3B%26%231007%3B%26%2311411%3B%26%2311423%3B%26%2311429%3B+gyptios%2C+kyptios%2C+and+from+there+into+Arabic+as+%2C+back+formed+into+%2C+whence+English+Copt.%22%3Bi%3A15%3Bs%3A209%3A%22The+Greek+forms+were+borrowed+from+Late+Egyptian++Hikuptah+%22Memphis%22%2C+a+corruption+of+the+earlier+Egyptian+name+Hwt-ka-Ptah+%2C+meaning+%22home+of+the+ka++of+Ptah%22%2C+the+name+of+a+temple+to+the+god+Ptah+at+Memphis.%22%3Bi%3A16%3Bs%3A130%3A%22Strabo+attributed+the+word+to+a+folk+etymology+in+which+A%26iacute%3Bgyptos++evolved+as+a+compound+from++%2C+meaning+%22below+the+Aegean%22.%22%3Bi%3A17%3Bs%3A288%3A%22%2C+the+Arabic+and+modern+official+name+of+Egypt+%2C+is+of+Semitic+origin%2C+directly+cognate+with+other+Semitic+words+for+Egypt+such+as+the+Hebrew+%26lrm%3B+%2C+literally+meaning+%22the+two+straits%22+.+The+word+originally+connoted+%22metropolis%22+or+%22civilization%22+and+means+%22country%22%2C+or+%22frontier-land%22.%22%3Bi%3A18%3Bs%3A232%3A%22The+ancient+Egyptian+name+of+the+country+is+Kemet++%5B%26%2378222%3B%26%2378163%3B%26%2378799%3B%26%2378486%3B%5D%2C+which+means+%22black+land%22%2C+referring+to+the+fertile+black+soils+of+the+Nile+flood+plains%2C+distinct+from+the+deshret+%2C+or+%22red+land%22+of+the+desert.%22%3Bi%3A19%3Bs%3A152%3A%22The+name+is+realized+as++and++in+the+Coptic+stage+of+the+Egyptian+language%2C+and+appeared+in+early+Greek+as++.+Another+name+was++%22land+of+the+riverbank%22.%22%3Bi%3A20%3Bs%3A105%3A%22The+names+of+Upper+and+Lower+Egypt+were+Ta-Sheme%27aw++%22sedgeland%22+and+Ta-Mehew++%22northland%22%2C+respectively.%22%3Bi%3A21%3Bs%3A79%3A%22There+is+evidence+of+rock+carvings+along+the+Nile+terraces+and+in+desert+oases.%22%3Bi%3A22%3Bs%3A103%3A%22In+the+10th+millennium+BC%2C+a+culture+of+hunter-gatherers+and+fishers+replaced+a+grain-grinding+culture.%22%3Bi%3A23%3Bs%3A117%3A%22Climate+changes+and%2For+overgrazing+around+8000+BC+began+to+desiccate+the+pastoral+lands+of+Egypt%2C+forming+the+Sahara.%22%3Bi%3A24%3Bs%3A129%3A%22Early+tribal+peoples+migrated+to+the+Nile+River+where+they+developed+a+settled+agricultural+economy+and+more+centralized+society.%22%3Bi%3A25%3Bs%3A63%3A%22By+about+6000+BC+a+Neolithic+culture+rooted+in+the+Nile+Valley.%22%3Bi%3A26%3Bs%3A104%3A%22During+the+Neolithic+era%2C+several+predynastic+cultures+developed+independently+in+Upper+and+Lower+Egypt.%22%3Bi%3A27%3Bs%3A108%3A%22The+Badarian+culture+and+the+successor+Naqada+series+are+generally+regarded+as+precursors+to+dynastic+Egypt.%22%3Bi%3A28%3Bs%3A100%3A%22The+earliest+known+Lower+Egyptian+site%2C+Merimda%2C+predates+the+Badarian+by+about+seven+hundred+years.%22%3Bi%3A29%3Bs%3A198%3A%22Contemporaneous+Lower+Egyptian+communities+coexisted+with+their+southern+counterparts+for+more+than+two+thousand+years%2C+remaining+culturally+distinct%2C+but+maintaining+frequent+contact+through+trade.%22%3B%7D"));
$sentences = $sentences_working; // change here for testing
foreach ($sentences as $sentence_key => $sentence)
{
if (preg_match('/[^\x20-\x7E]/', $sentence))
{
unset($sentences[$sentence_key]);
}
}
echo "<pre>";
print_r($sentences);
echo "</pre>";
要测试两个数组（更小和更大），只需更改第 12 行。发生了什么？