PHP 函数

字符串函数：

　　

    $name = "fakeface";
    $myname =substr($name,0,3);//输出前面三个字符 fak
    print $myname;
    $name = strtoupper($name); //小写
    print $name;
    $name = strtolower($name);、、大写
    print $name;
    $position = strpos($name,"c");//输出c的位置
    print $position;

数学函数：

　　

    $num = 123.123456;
    print round($num);//输出一个整数123
   print round($num,3);//输出数字并保留三位小数123.123
    rand(1,10);//在1,10随机生成一个数字

数组函数：

　　

    $fav_bands = array();
    array_push($fav_bands, "Maroon 5");//给数组添加元素
    array_push($fav_bands, "Bruno Mars");
    array_push($fav_bands, "Nickelback");
    array_push($fav_bands, "Katy Perry");
    array_push($fav_bands, "Macklemore");
    print count($fav_bands); 查看数组有多少元素


   $names = array("david","alana","violet","rory");
    sort($names);// array("alana","david","rory","violet")
    print join(", ", $names);// prints alana, david, rory, violet
    rsort($names);  // array("violet","rory","david","alana")