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<b><a href="index-18.html" >杂项函数库</a></b>
<p><b>create_function</b>
<p>(PHP4 >= 4.0.1)
<p>create_function --- 建立匿名函数
<p>语法 : string
create_function (string args, string code)
<p>说明 :
<p>从传递的参数建立一个匿名的函数，并且传回一个独一无二的名称。通常参数args将会传递成一个单引号字符串，而参数code也是如此，使用单引号字符串的理由是为了要从剖析中来保护变量名称，否则，如果你使用双引号的话，就必须要逃脱变量名称，例如
: \$avar。
<p>你可以使用这个函数，从执行时收集到的资讯来建立一个函数。
<p>Example
:
<p><?php
<p>
$newfunc = create_function('$a,$b','return "ln($a) + ln($b) = ".log($a
* $b);');
<p>
echo "New anonymous function: $newfunc\n";
<p>
echo $newfunc(2,M_E)."\n";
<p>
// outputs
<p>
// New anonymous function: lambda_1
<p>
// ln(2) + ln(2.718281828459) = 1.6931471805599
<p>?>
<p>或者是拥有处理者(handler)函数，这可以请求一个运作的设定到一个参数的列表。
<p>Example
:
<p><?php
<p>
function process($var1, $var2, $farr) {
<p>
for ($f=0; $f < count($farr); $f++)
<p>
echo $farr[$f]($var1,$var2)."\n";
<p>
}
<p>
// create a bunch of math functions
<p>
$f1 = 'if ($a >=0) {return "b*a^2 = ".$b*sqrt($a);} else {return
false;}';
<p>
$f2 = "return \"min(b^2+a, a^2,b) =
\".min(\$a*\$a+\$b,\$b*\$b+\$a);";
<p>
$f3 = 'if ($a > 0 && $b != 0) {return "ln(a)/b = ".log($a)/$b;}
else {return false;}';
<p>
$farr = array(
<p>
create_function('$x,$y', 'return "some trig: ".(sin($x) + $x*cos($y));'),
<p>
create_function('$x,$y', 'return "a hypotenuse: ".sqrt($x*$x +
$y*$y);'),
<p>
create_function('$a,$b', $f1), create_function('$a,$b', $f2),
<p>
create_function('$a,$b', $f3)
<p>
);
<p>
echo "\nUsing the first array of anonymous functions\n";
<p>
echo "parameters: 2.3445, M_PI\n";
<p>
process(2.3445, M_PI, $farr);
<p>
// now make a bunch of string processing functions
<p>
$garr = array(
<p>
create_function('$b,$a','if (strncmp($a,$b,3) == 0) return "**
\"$a\" '.
<p>
'and \"$b\"\n** Look the same to me! (looking at the first 3
chars)";'),
<p>
create_function('$a,$b','; return "CRCs: ".crc32($a)." ,
".crc32(b);'),
<p>
create_function('$a,$b','; return "similar(a,b) = ".similar_text($a,$b,&$p)."($p%)";')
<p>
);
<p>
echo "\nUsing the second array of anonymous functions\n";
<p>
process("Twas brilling and the slithy toves", "Twas the
night", $garr);
<p>?>
<p>当你执行上面的范例时，输出将会是 :
<p>Using the first array of anonymous
functions
<p>parameters: 2.3445, M_PI
<p>some trig: -1.6291725057799
<p>a hypotenuse: 3.9199852871011
<p>b*a^2 = 4.8103313314525
<p>min(b^2+a, a^2,b) = 8.6382729035898
<p>ln(a/b) = 0.27122299212594
<p>Using the second array of anonymous
functions
<p>** "Twas the night" and "Twas
brilling and the slithy toves"
<p>** Look the same to me! (looking at the first
3 chars)
<p>CRCs: -725381282 , 1908338681
<p style="margin-bottom: 0">similar(a,b) = 11(45.833333333333%)
<p style="margin-bottom: 0">匿名函数常见的使用是用来建立callback函数，例如 : 当使用<a href="array_walk.html" >array_walk(
)</a>或<a href="usort.html" >usort( )</a>时 :
<p><?php
<p>
$av = array("the ","a ","that ","this
");
<p>
array_walk($av, create_function('&$v,$k','$v = $v."mango";'));
<p>
print_r($av); // for PHP3 use var_dump( )
<p>
// outputs:
<p>
// Array
<p>
// (
<p>
// [0] => the mango
<p>
// [1] => a mango
<p>
// [2] => that mango
<p>
// [3] => this mango
<p>
// )
<p>
// an array of strings ordered from shorter to longer
<p> $sv = array("small","larger","a big
string","it is a string thing");
<p> print_r($sv);
<p> // outputs:
<p> // Array
<p> // (
<p> // [0] => small
<p> // [1] => larger
<p> // [2] => a big string
<p> // [3] => it is a string
thing
<p> // )
<p> // sort it from longer to shorter
<p> usort($sv, create_function('$a,$b','return strlen($b) - strlen($a);'));
<p> print_r($sv);
<p> // out
PHP函数大全（浏览器即可打开超完美）
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PHP函数大全（浏览器即可打开超完美） （723个子文件） 
index.htm 4KB index.htm 314B
create_function.html 9KB add.html 8KB index-13.html 8KB index-19.html 7KB index-26.html 6KB index-1.html 6KB jdmonthname.html 6KB fopen.html 5KB mysql_fetch_field.html 5KB pfpro_process.html 4KB header.html 4KB index-3.html 4KB phpcredits.html 4KB pack.html 4KB date.html 4KB index-21.html 4KB setcookie.html 4KB strftime.html 4KB jddayofweek.html 4KB fsockopen.html 4KB array_splice.html 3KB strnatcmp.html 3KB get_browser.html 3KB index-31.html 3KB call_user_method.html 3KB index-10.html 3KB imagecreatefromgif.html 3KB highlight_file.html 3KB imagecreatefromjpeg.html 3KB imagecreatefrompng.html 3KB sprintf.html 3KB error_log.html 3KB unserialize.html 3KB mysql_query.html 3KB assert_options.html 3KB index-18.html 3KB func_get_args.html 3KB ereg_replace.html 3KB mysql_field_type.html 3KB array_multisort.html 3KB substr_replace.html 3KB serialize.html 3KB mktime.html 3KB pspell_new.html 3KB get_required_files.html 3KB mysql_data_seek.html 3KB imagettftext.html 3KB fscanf.html 2KB extract.html 2KB pfpro_process_raw.html 2KB fgetcsv.html 2KB imagepstext.html 2KB getimagesize.html 2KB index-25.html 2KB get_html_translation_table.html 2KB exec.html 2KB sscanf.html 2KB each.html 2KB imageloadfont.html 2KB strpos.html 2KB func_get_arg.html 2KB substr.html 2KB read_exif_data.html 2KB imagettfbbox.html 2KB sort.html 2KB ereg.html 2KB error_reporting.html 2KB mysql_fetch_array.html 2KB mysql_fetch_object.html 2KB index-24.html 2KB wddx_serialize_vars.html 2KB mysql_connect.html 2KB index-30.html 2KB snmp_set_quick_print.html 2KB get_loaded_extensions.html 2KB array_walk.html 2KB str_pad.html 2KB fgets.html 2KB uksort.html 2KB list.html 2KB snmpwalkoid.html 2KB apache_lookup_uri.html 2KB strtok.html 2KB split.html 2KB krsort.html 2KB rsort.html 2KB system.html 2KB imagepsbbox.html 2KB asort.html 2KB strtr.html 2KB urldecode.html 2KB array_merge_recursive.html 2KB file.html 2KB crypt.html 2KB array_slice.html 2KB mysql_pconnect.html 2KB strnatcasecmp.html 2KB fread.html 2KB共 723 条
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资源评论
niceboy7522013-05-06好东西，学了不少以前忽略的函数
liq20082012-12-04东西不错，谢了 不过，缺mysql函数
松鼠并并2013-01-14东西还可以，不过我主要是为了找MySQL函数的，没有用到。
