字符串函数：
1 $name = "fakeface"; 2 $myname =substr($name,0,3);//输出前面三个字符 fak 3 print $myname; 4 $name = strtoupper($name); //小写 5 print $name; 6 $name = strtolower($name);、、大写 7 print $name; 8 $position = strpos($name,"c");//输出c的位置 9 print $position;
数学函数：
1 $num = 123.123456; 2 print round($num);//输出一个整数123 3 print round($num,3);//输出数字并保留三位小数123.123 4 rand(1,10);//在1,10随机生成一个数字
数组函数：
1 $fav_bands = array(); 2 array_push($fav_bands, "Maroon 5");//给数组添加元素 3 array_push($fav_bands, "Bruno Mars"); 4 array_push($fav_bands, "Nickelback"); 5 array_push($fav_bands, "Katy Perry"); 6 array_push($fav_bands, "Macklemore"); 7 print count($fav_bands); 查看数组有多少元素 8 9 10 $names = array("david","alana","violet","rory"); 11 sort($names);// array("alana","david","rory","violet") 12 print join(", ", $names);// prints alana, david, rory, violet 13 rsort($names); // array("violet","rory","david","alana")