ref

How to properly reference local resources in HTML?

由 旧巷老猫 提交于 2019-11-26 21:29:33
As it turns out, referencing local resources can be a rub point for some. I'm looking for a canonical answer to local resource referencing, and what they mean. Take these examples, what is the difference between these reference paths? <img src="myfile.png" /> (no leading slash) <img src="/myfile.png" /> (with leading slash) <img src="folder/myfile.png" /> (no leading slash / in subfolder) <img src="/folder/myfile.png" /> (with leading slash / in sub folder) <img src="../folder/myfile.png" /> (with dots and a leading slash / in sub folder) A leading slash tells the browser to start at the root

how does this fix the state closure problem with react hooks?

由 女生的网名这么多〃 提交于 2019-11-26 17:53:30
问题 I am looking at the code in formik that apparently is a way around the stale closure problem with react hooks. function useEventCallback<T extends (...args: any[]) => any>(fn: T): T { const ref: any = React.useRef(); // we copy a ref to the callback scoped to the current state/props on each render useIsomorphicLayoutEffect(() => { ref.current = fn; }); return React.useCallback( (...args: any[]) => ref.current.apply(void 0, args), [] ) as T; } I've seen this pattern a lot in other libs but I

PHP and MySQLi - Cannot pass parameter 2 by reference in

由 烂漫一生 提交于 2019-11-26 14:48:56
问题 i am trying to make a function which will check update and insert some datas but i am having an issue in the first step where the $stmt->bind_param is saying that is not passing parameters by reference or something like that. I searched over internet but nothing was around so i dont know what to do with it. I have attached below the function code: public function killTarget($killerid,$victimiid,$victimcode) { if ($this->checkUsercode($victimcode,$victimiid)) { $stmt = $this->_db->prepare(

Assigning out/ref parameters in Moq

由 耗尽温柔 提交于 2019-11-26 00:53:58
问题 Is it possible to assign an out / ref parameter using Moq (3.0+)? I\'ve looked at using Callback() , but Action<> does not support ref parameters because it\'s based on generics. I\'d also preferably like to put a constraint ( It.Is ) on the input of the ref parameter, though I can do that in the callback. I know that Rhino Mocks supports this functionality, but the project I\'m working on is already using Moq. 回答1: Moq version 4.8 (or later) has much improved support for by-ref parameters:

When to use ref and when it is not necessary in C#

由 让人想犯罪 __ 提交于 2019-11-26 00:46:51
问题 I have a object that is my in memory state of the program and also have some other worker functions that I pass the object to to modify the state. I have been passing it by ref to the worker functions. However I came across the following function. byte[] received_s = new byte[2048]; IPEndPoint tmpIpEndPoint = new IPEndPoint(IPAddress.Any, UdpPort_msg); EndPoint remoteEP = (tmpIpEndPoint); int sz = soUdp_msg.ReceiveFrom(received_s, ref remoteEP); It confuses me because both received_s and

What&#39;s the difference between the &#39;ref&#39; and &#39;out&#39; keywords?

由 半腔热情 提交于 2019-11-25 23:28:41
问题 I\'m creating a function where I need to pass an object so that it can be modified by the function. What is the difference between: public void myFunction(ref MyClass someClass) and public void myFunction(out MyClass someClass) Which should I use and why? 回答1: ref tells the compiler that the object is initialized before entering the function, while out tells the compiler that the object will be initialized inside the function. So while ref is two-ways, out is out-only. 回答2: The ref modifier

Why use the &#39;ref&#39; keyword when passing an object?

由 我的梦境 提交于 2019-11-25 23:11:10
问题 If I am passing an object to a method, why should I use the ref keyword? Isn\'t this the default behaviour anyway? For example: class Program { static void Main(string[] args) { TestRef t = new TestRef(); t.Something = \"Foo\"; DoSomething(t); Console.WriteLine(t.Something); } static public void DoSomething(TestRef t) { t.Something = \"Bar\"; } } public class TestRef { public string Something { get; set; } } The output is \"Bar\" which means that the object was passed as a reference. 回答1:

When to use ref and when it is not necessary in C#

由 丶灬走出姿态 提交于 2019-11-25 20:48:09
I have a object that is my in memory state of the program and also have some other worker functions that I pass the object to to modify the state. I have been passing it by ref to the worker functions. However I came across the following function. byte[] received_s = new byte[2048]; IPEndPoint tmpIpEndPoint = new IPEndPoint(IPAddress.Any, UdpPort_msg); EndPoint remoteEP = (tmpIpEndPoint); int sz = soUdp_msg.ReceiveFrom(received_s, ref remoteEP); It confuses me because both received_s and remoteEP are returning stuff from the function. Why does remoteEP need a ref and received_s does not? I am
订阅 ref