小编lor*_*ier的帖子

我是ruby和rails的新手,遇到了一个相当奇怪的错误:

class Person < ActiveRecord::Base
    validates_presence_of :description, :if => require_description_presence?

    def require_description_presence?
        self.can_send_email
    end
end

加薪

NoMethodError in PeopleController#index

undefined method `require_description_presence?' for #<Class:0x4c4fadc> 

我一直在尝试在php下实现合并排序.但似乎不成功:(找不到错误的来源.非常感谢任何一种帮助!

function merge_sort(&$input, $start, $end) {
    if($start < $end) {
        $mid = (int) floor($start + $end / 2);
        merge_sort($input, $start, $mid);
        merge_sort($input, $mid + 1, $end);
        merge($input, $start, $mid, $end);
    } 
}

function merge(&$input, $p, $q, $r) { 
    $a = $q - $p + 1;
    $b = $r - $q;

    for($i = $p;$i <= $q;$i++) {
        $arr1[] = $input[$i];
    }

    for($i = $q+1;$i <= $r;$i++) {
        $arr2[] = $input[$i];
    }   

    $c = $d = 0;
    for($i = $p; $i <= …