PHP代码开启错误信息提示方法

错误信息提示就是在程序开发测试时碰到错误给出提示了，今天我们来看一篇关于PHP代码开启错误信息提示方法，具体的细节步骤如下文介绍。

不显示调试错误

之前没有开启之前，出现这样的错误提示，并不是我们希望的，这样没有给我们任何有意义的调试信息：

解决办法

在入口处统一设置如下代码即可：

 ini_set("display_errors", "On");
error_reporting(E_ALL);

php.ini的话,代码如下:

找到display_errors = On 修改为 display_errors = off

下面我们来看一篇关于PHP “Notice: Undefined variable” 和 “Notice: Undefined index”报错，希望这篇文章能够帮助到各位朋友，有兴趣的朋友可以进来看看吧。

解决Notice: Undefined variable报错

虽然 PHP不需要预先声明变量，但是依然强烈推荐大家声明以避免因为忘记给变量赋值而引起的一些安全性漏洞及可能的BUG。所以PHP以非常低的报警级别(E_NOTICE)来提醒大家正在使用一个未声明的变量。

当然解决以上报错有如下几种方法，根据场景选择适合自己的：

1.（推荐）提前声明变量，例如当你想要为一个未声明的变量连接字符串的时候。或者使用isset()/!empty()来检查是否已经声明：

$value = ""; //初始化变量
             //"" 当下面需要对其进行字符串操作时
             //0  当下面需要对其数字操作时
//isset()
$value = isset($_POST['value']) ? $_POST['value'] : '';
//empty()
$value = !empty($_POST['value']) ? $_POST['value'] : '';
2.设置自定义的(error handler)来处理E_NOTICE错误

set_error_handler('myHandlerForMinorErrors', E_NOTICE | E_STRICT)
3.禁止E_NOTICE报警

error_reporting( error_reporting() & ~E_NOTICE )
强烈建议使用第一种方法

解决Notice: Undefined index报错

当你访问数组中尚未定义的索引时会出现 Undefined index问题。

1.在访问数组索引前检查是否存在，可以使用isset()或者array_key_exists()

//isset()
$value = isset($array['my_index']) ? $array['my_index'] : '';
//array_key_exists()
$value = array_key_exists('my_index', $array) ? $array['my_index'] : '';

数组处理我们php包括了许多的函数具体有哪些函数我们一起来看看小编为各位整理的PHP处理数组常用函数汇总的例子，具体的细节如下介绍。

PHP中对数组的处理是最常用的必备技能之一。自己总结了一下几个最常用的处理数组的高级函数。

1. array_merge()

合并数组，将一个或多个数组的单元合并起来，一个数组中的值附加在前一个数组的后面，最后返回一个数组。
关联数组:有相同的字符串键名时，则该键名后面的值将覆盖前一个值
索引数组:后面的值将不会覆盖原来的值，而是附加到后面

array array_merge (array array1 array2…,arrayN) 
例子：

<?php 
$a = array("a","b","c"); 
$b = array("1","2","3"); 
$c = array_merge($a, $b); 
print_r($c); 
 
// 输出结果
// Array ( [0] => a [1] => b [2] => c [3] => 1 [4] => 2 [5] => 3 ) 
?>

2. array_merge_recursive()

功能同array_merge()，只不过遇到相同值时处理方式不同
关联数组：有相同的字符串键名时，则该键值变成一个数组，将相同键值放在一个数组里

例子:

<?php 
$a = array("a" => "123", "b" => "yes"); 
$b = array("c" => "no", "a" => "aaa"); 
$d = array_merge_recursive($a, $b); 
print_r($d); 
 
// 输出结果 
// Array ( [a] => Array ( [0] => 123 [1] => aaa ) [b] => yes [c] => no ) 
?> 

3. array_slice()

拆分索引数组,类似于substr()的用法, offset开始切,切length这么多个, 不设置length则是切到尾

array array_slice (array array, int offset[,int length]) 
例子:

<?php 
 
$a = array("A", "B", "C", "D", "E", "F", "G"); 
$b = array_slice($a, 3); 
print_r($b); 
 
// 输出 
// Array ( [0] => D [1] => E [2] => F [3] => G ) 
?> 

4. array_multisort()

返回排序数组:

array_multisort(array1,sorting order,sorting type,array2,array3...)

这个函数功能很强大,有几个用法:

直接进行排序

<?php
$a1=array("Dog","Cat");
$a2=array("Fido","Missy");
array_multisort($a1,$a2);
print_r($a1);
print_r($a2);

// Array ( [0] => Cat [1] => Dog ) Array ( [0] => Missy [1] => Fido )
?>

设置排序方式进行排序

<?php
/* 设置倒序正序 */
$a1=array("Dog","Dog","Cat");
$a2=array("Pluto","Fido","Missy");
array_multisort($a1,SORT_ASC,$a2,SORT_DESC);
print_r($a1);
print_r($a2);

// Array ( [0] => Cat [1] => Dog [2] => Dog ) Array ( [0] => Missy [1] => Pluto [2] => Fido )

/* 设置倒序正序,排序标准 */
$a1=array(1,30,15,7,25);
$a2=array(4,30,20,41,66);
$num=array_merge($a1,$a2);
array_multisort($num,SORT_DESC,SORT_NUMERIC);
print_r($num);

// Array ( [0] => 66 [1] => 41 [2] => 30 [3] => 30 [4] => 25 [5] => 20 [6] => 15 [7] => 7 [8] => 4 [9] => 1 )
?>

二维数组根据某键值进行排序

<?php
/* time为要排序字段, SORT_DESC降序排列, $all要排序的数组 */
foreach ($all as $k => $v)
{
    $time[] = $v['time'];
}
array_multisort($time, SORT_DESC, $all);
?>

5. array_intersect()和array_intersect_assoc()

array_intersect()返回一个保留了键的数组，这个数组只由第一个数组中出现的且在其他每个输入数组中都出现的值组成。
array_intersect_assoc()返回一个在第一个数组中出现，且在所有其他输入数组中也出现的键/值对组成的数组。
应用场景: 共同好友推荐

<?php 
$a = array("Kevin","Mike","Jone"); 
$b = array("Jack","Kevin","Anna"); 
$c = array("Steven","Json","Kevin"); 
$output = array_intersect($a, $b, $c); 
print_r($output); 
 
// output 
// Array ( [0] => Kevin ) 
?> 

上传文件我们必须得知道上传文件的类型了并不是直接获得后缀名了，这种做法是非常的不安全了，下面我们给各位整理了真正的判断用户上传文件类型的一些方法汇总。

1、mime_content_type()函数判断获取文件类型

 mime_content_type返回指定文件的MIME类型，

用法：

代码如下	复制代码
echomime_content_type('php.gif') ."n"; echomime_content_type('test.php'); 输出： image/gif text/plain

但是php 5.3.0已经将该函数废弃。如果仍想使用此函数，那么可以对php进行配置启用magic_mime扩展。

2、php Fileinfo 获取文件类型(finfo_open)

 PHP官方推荐mime_content_type()的替代函数是Fileinfo函数。PHP 5.3.0+已经默认支持Fileinfo函数(fileinfo support-enabled)，不必进行任何配置即可使用finfo_open()判断获取文件MIME类型。
用法：

代码如下	复制代码
$finfo   = finfo_open(FILEINFO_MIME); $mimetype = finfo_file($finfo, $filename); finfo_close($finfo);

3、image_type_to_mime_type()获取图片类型

 如果需要判断MIME类型的文件只有图像文件，那么首先可以使用exif_imagetype()函数获取图像类型常量，再用image_type_to_mime_type()函数将图像类型常量转换成图片文件的MIME类型。
注意：

需要在php.ini中配置打开php_mbstring.dll (Windows需要)和extension=php_exif.dll。

4、php获取上传文件类型

如果使用php上传文件，检测上传文件的MIME类型，则可以使用全局变量$_FILES['uploadfile']['type']，由客户端的浏览器检测获取文件MIME类型。

 下面直接上代码，相信略有些php功底的朋友，读来都不成问题。我实现的是仅支持word和pdf文件，且文件大小小于512kb:

代码如下

复制代码

$tmpname = $_FILES ['userfile'] ['tmp_name'];  if(is_uploaded_file($tmpname)) {   $mimetype = detectMIME($tmpname);   $tuozhanming = getFileExt($filename, $mimetype);   if($tuozhanming == "type_error"){    echo '仅支持word和pdf文件，且文件大小小于512kb:<a href='.$reurl.'>请重试</a>';    exit();   }  }else{   $_FILES ['userfile'] ['error'] = 6;  }  if ($_FILES ['userfile'] ['error'] > 0) {   echo 'Problem: ';   switch ($_FILES ['userfile'] ['error']) {    case 1 :     echo '上传文件过大:<a href='.$reurl.'>请重试</a>';     break;    case 2 :     echo '上传文件过大:<a href='.$reurl.'>请重试</a>';     break;    case 3 :     echo '文件上传丢失:<a href='.$reurl.'>请重试</a>';     break;    case 4 :     echo '无文件被上传:<a href='.$reurl.'>请重试</a>';     break;    case 6 :     echo '仅支持word和pdf文件，且文件大小小于512kb:<a href='.$reurl.'>请重试</a>';     break;    case 7 :     echo '上传文件存储失败:<a href='.$reurl.'>请重试</a>';     break;   }   exit ();  }  //判断文件类型  //上传文件  $_FILES ['userfile'] ['name'] = time () . "." . $tuozhanming;  $upfile = '../uploads/' . $_FILES ['userfile'] ['name'];  if ( !move_uploaded_file ( $_FILES ['userfile'] ['tmp_name'], $upfile )) {   echo 'Problem: 文件移动失败';   exit ();  }   } function detectMIME($filename) {  $file = fopen ( $filename, "rb" );  $finfo = finfo_open ( FILEINFO_MIME );  if (! $finfo) {   // 直接读取文件的前4个字节，根据硬编码判断   $file = fopen ( $filename, "rb" );   $bin = fread ( $file, 4 ); //只读文件头4字节   fclose ( $file );   $strInfo = @unpack ( "C4chars", $bin );   //dechex() 函数把十进制转换为十六进制。   $typeCode = dechex ( $strInfo ['chars1'] ) .                             dechex ( $strInfo ['chars2'] ) .                             dechex ( $strInfo ['chars3'] ) .                             dechex ( $strInfo ['chars4'] );   $type = '';   switch ($typeCode) //硬编码值查表   {    case "504b34" :     $type = 'application/zip; charset=binary';     break;    case "d0cf11e0" :     $type = 'application/vnd.ms-office; charset=binary';     break;    case "25504446" :     $type = 'application/pdf; charset=binary';     break;    default :     $type = 'application/vnd.ms-office; charset=binary';     break;   }  } else {   //finfo_file return information of a file   $type = finfo_file ( $finfo, $filename );  }  return $type; function getFileExt($filename, $type) {  switch ($type) {   case "application/zip; charset=binary" :    $extType = "docx";    break;   case "application/vnd.ms-office; charset=binary" :    $extType = "doc";    break;   case "application/msword; charset=binary" :        $extType = "doc";       break;   case "application/pdf; charset=binary" :    $extType = "pdf";    break;   default :    $extType = "type_error";    break;  }  return $extType; }

方法五，网上流传一段PHP读取文件头判断文件类型的方法，有一些bug，经我（54chen）修改实测，应该是这个样子：

代码如下

复制代码

/** * 读取文件前几个字节 判断文件类型 * * @return String */ function checkTitle($filename) { $file     = fopen($filename, "rb"); $bin      = fread($file, 2); //只读2字节 fclose($file); $strInfo  = @unpack("c2chars", $bin); $typeCode = intval($strInfo['chars1'].$strInfo['chars2']); $fileType = ''; switch ($typeCode) { case 7790: $fileType = 'exe'; break; case 7784: $fileType = 'midi'; break; case 8297: $fileType = 'rar'; break; case 255216: $fileType = 'jpg'; break; case 7173: $fileType = 'gif'; break; case 6677: $fileType = 'bmp'; break; case 13780: $fileType = 'png'; break; default: $fileType = 'unknown'.$typeCode; } //Fix if ($strInfo['chars1']=='-1' && $strInfo['chars2']=='-40' ) { return 'jpg'; } if ($strInfo['chars1']=='-119' && $strInfo['chars2']=='80' ) { return 'png'; } return $fileType; }

对于上传文件类型的判断，一直没有太好的办法，即使使用上面的代码，也有办法构造假的图片的（如何构造不再传播），有人使用getimagesize来判断，不失为一种好办法：

代码如下	复制代码
if(in_array($attach['ext'], array('jpg', 'jpeg', 'gif', 'png', 'swf', 'bmp')) && function_exists('getimagesize') && !@getimagesize($target)) {     @unlink($target);     upload_error('post_attachment_ext_notallowed', $attacharray);    }

补充:文件类型 值大全 .

123 application/vnd.lotus-1-2-3
3gp video/3gpp
aab application/x-authoware-bin
aam application/x-authoware-map
aas application/x-authoware-seg
ai application/postscript
aif audio/x-aiff
aifc audio/x-aiff
aiff audio/x-aiff
als audio/X-Alpha5
amc application/x-mpeg
ani application/octet-stream
asc text/plain
asd application/astound
asf video/x-ms-asf
asn application/astound
asp application/x-asap
asx video/x-ms-asf
au audio/basic
avb application/octet-stream
avi video/x-msvideo
awb audio/amr-wb
bcpio application/x-bcpio
bin application/octet-stream
bld application/bld
bld2 application/bld2
bmp application/x-MS-bmp
bpk application/octet-stream
bz2 application/x-bzip2
cal image/x-cals
ccn application/x-cnc
cco application/x-cocoa
cdf application/x-netcdf
cgi magnus-internal/cgi
chat application/x-chat
class application/octet-stream
clp application/x-msclip
cmx application/x-cmx
co application/x-cult3d-object
cod image/cis-cod
cpio application/x-cpio
cpt application/mac-compactpro
crd application/x-mscardfile
csh application/x-csh
csm chemical/x-csml
csml chemical/x-csml
css text/css
cur application/octet-stream
dcm x-lml/x-evm
dcr application/x-director
dcx image/x-dcx
dhtml text/html
dir application/x-director
dll application/octet-stream
dmg application/octet-stream
dms application/octet-stream
doc application/msword
dot application/x-dot
dvi application/x-dvi
dwf drawing/x-dwf
dwg application/x-autocad
dxf application/x-autocad
dxr application/x-director
ebk application/x-expandedbook
emb chemical/x-embl-dl-nucleotide
embl chemical/x-embl-dl-nucleotide
eps application/postscript
eri image/x-eri
es audio/echospeech
esl audio/echospeech
etc application/x-earthtime
etx text/x-setext
evm x-lml/x-evm
evy application/x-envoy
exe application/octet-stream
fh4 image/x-freehand
fh5 image/x-freehand
fhc image/x-freehand
fif image/fif
fm application/x-maker
fpx image/x-fpx
fvi video/isivideo
gau chemical/x-gaussian-input
gca application/x-gca-compressed
gdb x-lml/x-gdb
gif image/gif
gps application/x-gps
gtar application/x-gtar
gz application/x-gzip
hdf application/x-hdf
hdm text/x-hdml
hdml text/x-hdml
hlp application/winhlp
hqx application/mac-binhex40
htm text/html
html text/html
hts text/html
ice x-conference/x-cooltalk
ico application/octet-stream
ief image/ief
ifm image/gif
ifs image/ifs
imy audio/melody
ins application/x-NET-Install
ips application/x-ipscript
ipx application/x-ipix
it audio/x-mod
itz audio/x-mod
ivr i-world/i-vrml
j2k image/j2k
jad text/vnd.sun.j2me.app-descriptor
jam application/x-jam
jar application/java-archive
jnlp application/x-java-jnlp-file
jpe image/jpeg
jpeg image/jpeg
jpg image/jpeg
jpz image/jpeg
js application/x-javascript
jwc application/jwc
kjx application/x-kjx
lak x-lml/x-lak
latex application/x-latex
lcc application/fastman
lcl application/x-digitalloca
lcr application/x-digitalloca
lgh application/lgh
lha application/octet-stream
lml x-lml/x-lml
lmlpack x-lml/x-lmlpack
lsf video/x-ms-asf
lsx video/x-ms-asf
lzh application/x-lzh
m13 application/x-msmediaview
m14 application/x-msmediaview
m15 audio/x-mod
m3u audio/x-mpegurl
m3url audio/x-mpegurl
ma1 audio/ma1
ma2 audio/ma2
ma3 audio/ma3
ma5 audio/ma5
man application/x-troff-man
map magnus-internal/imagemap
mbd application/mbedlet
mct application/x-mascot
mdb application/x-msaccess
mdz audio/x-mod
me application/x-troff-me
mel text/x-vmel
mi application/x-mif
mid audio/midi
midi audio/midi
mif application/x-mif
mil image/x-cals
mio audio/x-mio
mmf application/x-skt-lbs
mng video/x-mng
mny application/x-msmoney
moc application/x-mocha
mocha application/x-mocha
mod audio/x-mod
mof application/x-yumekara
mol chemical/x-mdl-molfile
mop chemical/x-mopac-input
mov video/quicktime
movie video/x-sgi-movie
mp2 audio/x-mpeg
mp3 audio/x-mpeg
mp4 video/mp4
mpc application/vnd.mpohun.certificate
mpe video/mpeg
mpeg video/mpeg
mpg video/mpeg
mpg4 video/mp4
mpga audio/mpeg
mpn application/vnd.mophun.application
mpp application/vnd.ms-project
mps application/x-mapserver
mrl text/x-mrml
mrm application/x-mrm
ms application/x-troff-ms
mts application/metastream
mtx application/metastream
mtz application/metastream
mzv application/metastream
nar application/zip
nbmp image/nbmp
nc application/x-netcdf
ndb x-lml/x-ndb
ndwn application/ndwn
nif application/x-nif
nmz application/x-scream
nokia-op-logo image/vnd.nok-oplogo-color
npx application/x-netfpx
nsnd audio/nsnd
nva application/x-neva1
oda application/oda
oom application/x-AtlasMate-Plugin
pac audio/x-pac
pae audio/x-epac
pan application/x-pan
pbm image/x-portable-bitmap
pcx image/x-pcx
pda image/x-pda
pdb chemical/x-pdb
pdf application/pdf
pfr application/font-tdpfr
pgm image/x-portable-graymap
pict image/x-pict
pm application/x-perl
pmd application/x-pmd
png image/png
pnm image/x-portable-anymap
pnz image/png
pot application/vnd.ms-powerpoint
ppm image/x-portable-pixmap
pps application/vnd.ms-powerpoint
ppt application/vnd.ms-powerpoint
pqf application/x-cprplayer
pqi application/cprplayer
prc application/x-prc
proxy application/x-ns-proxy-autoconfig
ps application/postscript
ptlk application/listenup
pub application/x-mspublisher
pvx video/x-pv-pvx
qcp audio/vnd.qcelp
qt video/quicktime
qti image/x-quicktime
qtif image/x-quicktime
r3t text/vnd.rn-realtext3d
ra audio/x-pn-realaudio
ram audio/x-pn-realaudio
rar application/x-rar-compressed
ras image/x-cmu-raster
rdf application/rdf+xml
rf image/vnd.rn-realflash
rgb image/x-rgb
rlf application/x-richlink
rm audio/x-pn-realaudio
rmf audio/x-rmf
rmm audio/x-pn-realaudio
rmvb audio/x-pn-realaudio
rnx application/vnd.rn-realplayer
roff application/x-troff
rp image/vnd.rn-realpix
rpm audio/x-pn-realaudio-plugin
rt text/vnd.rn-realtext
rte x-lml/x-gps
rtf application/rtf
rtg application/metastream
rtx text/richtext
rv video/vnd.rn-realvideo
rwc application/x-rogerwilco
s3m audio/x-mod
s3z audio/x-mod
sca application/x-supercard
scd application/x-msschedule
sdf application/e-score
sea application/x-stuffit
sgm text/x-sgml
sgml text/x-sgml
sh application/x-sh
shar application/x-shar
shtml magnus-internal/parsed-html
shw application/presentations
si6 image/si6
si7 image/vnd.stiwap.sis
si9 image/vnd.lgtwap.sis
sis application/vnd.symbian.install
sit application/x-stuffit
skd application/x-Koan
skm application/x-Koan
skp application/x-Koan
skt application/x-Koan
slc application/x-salsa
smd audio/x-smd
smi application/smil
smil application/smil
smp application/studiom
smz audio/x-smd
snd audio/basic
spc text/x-speech
spl application/futuresplash
spr application/x-sprite
sprite application/x-sprite
spt application/x-spt
src application/x-wais-source
stk application/hyperstudio
stm audio/x-mod
sv4cpio application/x-sv4cpio
sv4crc application/x-sv4crc
svf image/vnd
svg image/svg-xml
svh image/svh
svr x-world/x-svr
swf application/x-shockwave-flash
swfl application/x-shockwave-flash
t application/x-troff
tad application/octet-stream
talk text/x-speech
tar application/x-tar
taz application/x-tar
tbp application/x-timbuktu
tbt application/x-timbuktu
tcl application/x-tcl
tex application/x-tex
texi application/x-texinfo
texinfo application/x-texinfo
tgz application/x-tar
thm application/vnd.eri.thm
tif image/tiff
tiff image/tiff
tki application/x-tkined
tkined application/x-tkined
toc application/toc
toy image/toy
tr application/x-troff
trk x-lml/x-gps
trm application/x-msterminal
tsi audio/tsplayer
tsp application/dsptype
tsv text/tab-separated-values
tsv text/tab-separated-values
ttf application/octet-stream
ttz application/t-time
txt text/plain
ult audio/x-mod
ustar application/x-ustar
uu application/x-uuencode
uue application/x-uuencode
vcd application/x-cdlink
vcf text/x-vcard
vdo video/vdo
vib audio/vib
viv video/vivo
vivo video/vivo
vmd application/vocaltec-media-desc
vmf application/vocaltec-media-file
vmi application/x-dreamcast-vms-info
vms application/x-dreamcast-vms
vox audio/voxware
vqe audio/x-twinvq-plugin
vqf audio/x-twinvq
vql audio/x-twinvq
vre x-world/x-vream
vrml x-world/x-vrml
vrt x-world/x-vrt
vrw x-world/x-vream
vts workbook/formulaone
wav audio/x-wav
wax audio/x-ms-wax
wbmp image/vnd.wap.wbmp
web application/vnd.xara
wi image/wavelet
wis application/x-InstallShield
wm video/x-ms-wm
wma audio/x-ms-wma
wmd application/x-ms-wmd
wmf application/x-msmetafile
wml text/vnd.wap.wml
wmlc application/vnd.wap.wmlc
wmls text/vnd.wap.wmlscript
wmlsc application/vnd.wap.wmlscriptc
wmlscript text/vnd.wap.wmlscript
wmv audio/x-ms-wmv
wmx video/x-ms-wmx
wmz application/x-ms-wmz
wpng image/x-up-wpng
wpt x-lml/x-gps
wri application/x-mswrite
wrl x-world/x-vrml
wrz x-world/x-vrml
ws text/vnd.wap.wmlscript
wsc application/vnd.wap.wmlscriptc
wv video/wavelet
wvx video/x-ms-wvx
wxl application/x-wxl
x-gzip application/x-gzip
xar application/vnd.xara
xbm image/x-xbitmap
xdm application/x-xdma
xdma application/x-xdma
xdw application/vnd.fujixerox.docuworks
xht application/xhtml+xml
xhtm application/xhtml+xml
xhtml application/xhtml+xml
xla application/vnd.ms-excel
xlc application/vnd.ms-excel
xll application/x-excel
xlm application/vnd.ms-excel
xls application/vnd.ms-excel
xlt application/vnd.ms-excel
xlw application/vnd.ms-excel
xm audio/x-mod
xml text/xml
xmz audio/x-mod
xpi application/x-xpinstall
xpm image/x-xpixmap
xsit text/xml
xsl text/xml
xul text/xul
xwd image/x-xwindowdump
xyz chemical/x-pdb
yz1 application/x-yz1
z application/x-compress
zac application/x-zaurus-zac
zip application/zip