源代码:
<HTML> <HEAD></HEAD> <FONT FACE="'Courier New',Verdana, Arial, Helvetica" SIZE=2> <!DOCTYPE html> <html> <body> <FONT COLOR=#ff0000><?php $a=array("Volvo"=>"XC90","BMW"=>"X5","Toyota"=>"Highlander"); print_r(array_keys($a)); ?></FONT> </body> </html> </HTML>
运行结果：
<HTML> <HEAD></HEAD> <FONT FACE="'Courier New',Verdana, Arial, Helvetica" SIZE=2> <!DOCTYPE html> <html> <body> <FONT COLOR=#ff0000>Array ( [0] => Volvo [1] => BMW [2] => Toyota ) </FONT> </body> </html> </HTML>