10个php函数实用却不常见

$a = 0;  
function iterate() {  
global $a;  
if( $a < 10 )  
recur();  
echo $a . “, “;  
}  
function recur() {  
global $a;  
$a++;  
// how did I get here?  
echo “\n\n\n”;  
debug_print_backtrace();  
if( $a < 10 )  
iterate();  
}  
iterate();  
# OUTPUT:  
#0 recur() called at [C:\htdocs\php_stuff\index.php:8]  
#1 iterate() called at [C:\htdocs\php_stuff\index.php:25]  
#0 recur() called at [C:\htdocs\php_stuff\index.php:8]  
#1 iterate() called at [C:\htdocs\php_stuff\index.php:21]  
#2 recur() called at [C:\htdocs\php_stuff\index.php:8]  
#3 iterate() called at [C:\htdocs\php_stuff\index.php:25]  
#0 recur() called at [C:\htdocs\php_stuff\index.php:8]  
#1 iterate() called at [C:\htdocs\php_stuff\index.php:21]  
#2 recur() called at [C:\htdocs\php_stuff\index.php:8]  
#3 iterate() called at [C:\htdocs\php_stuff\index.php:21]  
#4 recur() called at [C:\htdocs\php_stuff\index.php:8]  
#5 iterate() called at [C:\htdocs\php_stuff\index.php:25] 

$items = array(  
“100 apples”, “5 apples”, “110 apples”, “55 apples”  
);  
// normal sorting:  
sort($items);  
print_r($items);  
# Outputs:  
# Array  
# (  
# [0] => 100 apples  
# [1] => 110 apples  
# [2] => 5 apples  
# [3] => 55 apples  
# )  
natsort($items);  
print_r($items);  
# Outputs:  
# Array  
# (  
# [2] => 5 apples  
# [3] => 55 apples  
# [0] => 100 apples  
# [1] => 110 apples  
# ) 

$dictionary = array(  
“php”, “javascript”, “css”  
);  
$word = “japhp”;  
$best_match = $dictionary[0];  
$match_value = levenshtein($dictionary[0], $word);  
foreach($dictionary as $w) {  
$value = levenshtein($word, $w);  
if( $value < $match_value ) {  
$best_match = $w;  
$match_value = $value;  
}  
}  
echo “Did you mean the ‘$best_match' category?”; 

foreach (glob(“*.php”) as $file)  
echo “$file\n”;