default-value

Is It Possible To Set Default Parameter Value On A Rest Parameter

由 ╄→尐↘猪︶ㄣ 提交于 2019-11-27 06:42:43
问题 ES6 introduces a bevy of convenient "syntactic sugar". Among them are the default parameter capabilities of JavaScript functions, as well as rest parameters. I'm finding that my console (or devTools) complains ( i.e. , throws an error) whenever attempting to set a default parameter value on a rest parameter. I've found surprisingly few references to this particular issue elsewhere and am wondering if 1.) it is possible to do so and 2.) why not (assuming it's not possible). As an example, I've

Unknown file type MIME?

由 房东的猫 提交于 2019-11-27 06:42:34
Do I have to specify a MIME type if the uploaded file has no extension? In other words is there a default general MIME type? You can use application/octet-stream for unknown types. RFC 2046 states in section 4.5.1: The "octet-stream" subtype is used to indicate that a body contains arbitrary binary data. RFC resources: We should use RFC-7231 (HTTP/1.1 Semantics and Content) as reference instead of RFC-2046 (Media Types) because question was clearly about HTTP Content-Type. Also RFC-2046 does not clearly define unknown types but RFC-7231 does. Short answer: Do not send MIME type for unknown

What is the default value of a member in an array?

由 早过忘川 提交于 2019-11-27 06:34:12
问题 I instantiate an array like this: int array[] = new int[4]; What are the default values for those four members? Is it null, 0 or not exists? 回答1: It's 0. It can't be null, as null isn't a valid int value. From section 7.6.10.4 of the C# 5 specification: All elements of the new array instance are initialized to their default values (§5.2). And from section 5.2: The default value of a variable depends on the type of the variable and is determined as follows: For a variable of a value-type, the

namedtuple and default values for optional keyword arguments

由 喜你入骨 提交于 2019-11-27 05:47:51
I'm trying to convert a longish hollow "data" class into a named tuple. My class currently looks like this: class Node(object): def __init__(self, val, left=None, right=None): self.val = val self.left = left self.right = right After conversion to namedtuple it looks like: from collections import namedtuple Node = namedtuple('Node', 'val left right') But there is a problem here. My original class allowed me to pass in just a value and took care of the default by using default values for the named/keyword arguments. Something like: class BinaryTree(object): def __init__(self, val): self.root =

What does 'value initializing' something mean? [duplicate]

由 China☆狼群 提交于 2019-11-27 05:29:10
问题 Possible Duplicate: What do the following phrases mean in C++: zero-, default- and value-initialization? If I have a class for example: class Info { int x; int y; }; which I used to created an object, Info *p = new Info(); Does the brackets beside Info mean i'm value initializing it? How does it different from this, Info *p = new Info; ? I know there is a question which differentiate between different meanings in new and old C++ language but I want to know the semantic difference between

Android CheckBoxPreference Default Value

由 眉间皱痕 提交于 2019-11-27 04:27:41
问题 I have the following XML code for my CheckBoxPreference : <CheckBoxPreference android:key="pref_boot_startup" android:title="Auto start" android:defaultValue="true" /> But when I retrieve the preference in code the value is false . sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this); boolean autoStart = sharedPreferences.getBoolean("pref_boot_startup", true); My autoStart variable returns false . Is there a specific reason for this? Am I missing a step to set the default

Is it possible to have a default parameter for a mysql stored procedure?

由 浪尽此生 提交于 2019-11-27 03:48:15
I have googled this and keep coming up with "No it is not possible" but these posts were dated 2005-2007 so I'm wondering if this has been changed. A code example: CREATE PROCEDURE `blah` ( myDefaultParam int = 0 -- This breaks the code for some reason ) BEGIN -- Do something here END One of the solutions has been to pass null and then check for null and set the variable. I don't want to do that and I shouldn't have to. If this is true then MySql devs need to wake up because there is so much more I could do with MSSQL. It's still not possible. We worked around this limitation by adding a

Delete default value of an input text on click

由 亡梦爱人 提交于 2019-11-27 02:57:58
I have an input text : <input name="Email" type="text" id="Email" value="email@abc.com" /> I want to put a default value like "What's your programming question ? be specific." in StackOverFlow, and when the user click on it the default value disapear. For future reference, I have to include the HTML5 way to do this. <input name="Email" type="text" id="Email" value="email@abc.com" placeholder="What's your programming question ? be specific." /> If you have a HTML5 doctype and a HTML5-compliant browser, this will work. However, many browsers do not currently support this , so at least Internet

Specifying default parameter when calling C++ function

由 拈花ヽ惹草 提交于 2019-11-27 02:40:53
问题 Suppose I have code like this: void f(int a = 0, int b = 0, int c = 0) { //...Some Code... } As you can evidently see above with my code, the parameters a , b , and c have default parameter values of 0. Now take a look at my main function below: int main() { //Here are 4 ways of calling the above function: int a = 2; int b = 3; int c = -1; f(a, b, c); f(a, b); f(a); f(); //note the above parameters could be changed for the other variables //as well. } Now I know that I can't just skip a

DefaultValue attribute is not working with my Auto Property

由 六月ゝ 毕业季﹏ 提交于 2019-11-27 02:36:07
问题 I have the following Auto Property [DefaultValue(true)] public bool RetrieveAllInfo { get; set; } when I try to use it inside the code i find the default false for is false I assume this is the default value to a bool variable, does anyone have a clue what is wrong!? 回答1: The DefaultValue attribute is only used to tell the Visual Studio Designers (for example when designing a form) what the default value of a property is. It doesn't set the actual default value of the attribute in code. More
订阅 default-value