I've got a table in MySQL lets just say for example its got two fields Username, GameName and Score. I want to calculate the rank of a user for an indivudal game name so I could do the query SELECT * FROM scores WHERE `GameName` = 'Snake' ORDER BY `Score` DESC to get a list of all users in order of highest to lowest and assign a number to each user. But is there an easier way to get the
我在MySQL中有一张表让我们只是说例如它有两个字段用户名，游戏名称和分数。 我想计算一个用户的等级为一个单独的游戏名称，所以我可以做这个查询 SELECT * FROM scores WHERE `GameName` = 'Snake' ORDER BY `Score` DESC 按照从高到低的顺序获得所有用户的列表，并为每个用户分配一个号码。 但是有没有一种更简单的方法来获得单个用户的排名，而不是选择整个表，因为这看起来效率不高。 谢谢 如果你想要整体排名，你
For example, is it possible to write code like this: int $x = 6; str $y = "hello world"; bool $z = false; MyObject $foo = new MyObject(); And is it possible to define functions like this: public int function getBalance() { return 555; //Or any numeric value } Edit: This answer applies to versions of PHP 5.6 and earlier. As noted in recent answers, PHP version 7.0 and later does have some
例如，是否可以像这样编写代码： int $x = 6; str $y = "hello world"; bool $z = false; MyObject $foo = new MyObject(); 是否可以定义这样的函数： public int function getBalance() { return 555; //Or any numeric value } 编辑：这个答案适用于PHP 5.6及更早版本。 正如最近的答案中指出的那样，PHP 7.0和更高版本确实对此有所支持 原始答案： 没有。从php5开始支持类型提示，但“类型提示只能是对象和数组（
How do I check if the request is an AJAX? I am using CodeIgniter. I have a link that when it clicked, it'll open the pop-up dialog window this is done through ajax it requests to a controller name login_window() . CodeIgniter //Here is the controller name: function login_window(){ // request via ajax $this->load->view("login_window"); } jQuery //here is the jquery code: /
如何检查请求是否是AJAX？ 我正在使用CodeIgniter。 我有一个链接，当它点击时，它会打开弹出对话窗口，这是通过ajax向控制器名称login_window()请求的。 笨 //Here is the controller name: function login_window(){ // request via ajax $this->load->view("login_window"); } jQuery的 //here is the jquery code: //I am using a jquery plugin FACEBOX $('a[rel*=dialog]').facebox(); <a href="
This question already has an answer here: 'AND' vs '&&' as operator 10 answers Both are same But && has higher precedence than AND REFERENCE
这个问题在这里已经有了答案： 'AND'和'&&'作为操作符10的答案 两者都是相同的，但&&比AND具有更高的优先级 参考
This question already has an answer here: 'AND' vs '&&' as operator 10 answers After some search I found out that this is caused by the operator precedence in PHP. The '=' operator is stronger than 'and'. If you want to get the expected result you have to use braces: $x = (true and false); //correct: $x is false now! Without braces the expression i
这个问题在这里已经有了答案： 'AND'和'&&'作为操作符10的答案 经过一番搜索后，我发现这是由PHP中的运算符优先级引起的。 '='运算符比'和'更强。 如果你想得到预期的结果，你必须使用大括号： $x = (true and false); //correct: $x is false now! 没有大括号的表达式等于($x = true) and false; 。 $ x将获得'真正'的价值。 之后，PHP解释器用$ x刚刚获得的值“替
This question already has an answer here: 'AND' vs '&&' as operator 10 answers and has a lower operator precedence than = so what you are executing is: ($x = true) and false; So the complete expression - which you don't use the result of - will return false , but $x will be true . It is because the and operator does not work as you think: 'AND' vs '
这个问题在这里已经有了答案： 'AND'和'&&'作为操作符10的答案 and运算符的优先级低于=所以你正在执行的是： ($x = true) and false; 所以完整表达式 - 你不使用结果 - 将返回false ，但是$x将是true 。 这是因为， and你想的运营商不工作：“和” VS“&&”作为运营商 基本上， =具有更高的优先级。 $x = false && true; var_dump($x); 返回bool(false) 。 一样 $x = (false
This question already has an answer here: 'AND' vs '&&' as operator 10 answers AND has lower precedence. $C = $A AND $B will be parsed as ($C = $A) AND $B . For variables $a and $b set as follows: <?php $a = 7; $b = 0; the advantage of using AND is short-circuit evaluation that occurs in code like the following: $c = $a AND $b; var_dump( $c ); // 7 Since th
这个问题在这里已经有了答案： 'AND'和'&&'作为操作符10的答案 AND具有较低的优先级。 $C = $A AND $B将被解析为($C = $A) AND $B 对于变量$ a和$ b设置如下： <?php $a = 7; $b = 0; 使用AND的优点是短路评估发生在代码中，如下所示： $c = $a AND $b; var_dump( $c ); // 7 由于赋值运算符具有比AND更高的优先级，$ a的值被赋值给$ c; $ b会被跳过。 相反，请考虑以下代码： <?
This question already has an answer here: 'AND' vs '&&' as operator 10 answers PHP：第一个代码将$ x设置为$ b与$ c的比较结果，两者都必须为真，第二个代码将设置$ y，如$ b和thant，将此成功与$ C The precedence of operators is what makes the difference here. PHP Operator Precedence JavaScript Operator Precedence
这个问题在这里已经有了答案： 'AND'和'&&'作为操作符10的答案 PHP：第一个代码将$ x设置为$ b与$ c的比较结果，两者都必须为真，第二个代码将设置$ y，如$ b和thant，将此成功与$ C 运营商的优先级是什么在这里有所作为。 PHP运算符优先级 JavaScript运算符优先级
This question already has an answer here: 'AND' vs '&&' as operator 10 answers Is there any difference between “and” and “&&” operators in PHP? [duplicate] 3 answers "||" has a greater precedence than "or" "&&" has a greater precedence than "and" From php manual, can read the full article here (Exemple1)
这个问题在这里已经有了答案： 'AND'和'&&'作为操作符10的答案 在PHP中，“和”和“&&”运算符有什么区别吗？ [重复] 3个答案 “||” 比“或”具有更高的优先级， “&&”的优先级高于“和” 从php手册，可以在这里阅读完整的文章（Exemple1）
This question already has an answer here: 'AND' vs '&&' as operator 10 answers PHP - and / or keywords 4 answers They do not have the same precedence. Fully parenthesised, your code is: ($keyWord = 2) and (3>4); // $keyWord = 2 $symbol = (2 && (3>4)); // $symbol = false 2 and false are clearly not the same, hence 'not-equal' . More on opera
这个问题在这里已经有了答案： 'AND'和'&&'作为操作符10的答案 PHP和/或关键字4的答案 它们不具有相同的优先级。 完全括号，您的代码是： ($keyWord = 2) and (3>4); // $keyWord = 2 $symbol = (2 && (3>4)); // $symbol = false 2和false显然是不一样的，因此'not-equal' 。 更多关于运营商优先权 那么，稍微改变一下代码就可以了： <?php $keyWord = 2 and 3