Programming to interface
What does it mean to "program to an interface"?
Possible Duplicate:             According to , Win 7 only supports 4 GB of RAM. I, however have been reading some forums and some say they are using 8 GB RAM with good performance. I am wondering if I can use 8 GB before I purchase. Would a Cup of Tea Be Hotter If you Add the Milk Before or After Boiling Water? This is a bit of dispute between work colleagues. An answer would be greatly appreciated.  My argument is as follows:  If you add X amount of milk at a temperature of M to a mug at room temperature R before adding X amount of water at temp W, the result would be a cooler cup of tea than if you'd added the hot water first. This would be due to the milk reducing the overall temperature of the mug in the time that has been in it resulting in the addition of boiling water having less of an effect and resulting in a slightly cooler cup of tea/coffee.   Conversely, if you add the hot water first, due to the mug being heated, the effect of adding the cool milk will be less and therefore the end result will be a hotter cup of tea.  My Colleagues arguement is simply that it would not make a difference but without any form of justification.   If anyone can give real scientific light to this issue it would be greatly appreciated :) Is there a command like "watch" or "inotifywait" on the Mac? Cannot connect MacBook Pro (Retina, 15-inch, Mid 2015) (10.13.3) to the internet through my Apple USB Ethernet Adapter. I am receiving this error under System Preferences/Network:   "Apple USB Ethernet Adapter has a self-assigned IP address and will not be able to connect to the Internet." IP Address: 169.254.59.248 Subnet Mask: 255.255.0.0   I can connect to the internet with the same ethernet port on my Windows 10 machine. When I replace the IP address with a the Wi-Fi IP address I use to successfully connect to the same network under "Using DHCP with manual address", the Apple USB Ethernet Adapter icon is green and displays the message "Apple USB Ethernet Adapter is currently active and has the IP address xx.xx.xx.252." However there is no actual internet connection (i.e., I cannot visit any website).  According to  to a similar problem, I can:   Find and disable whatever firewall is intercepting the DHCP return traffic. According to System Preferences/Security &amp; Privacy/Firewall, my firewall is off. Is there anywhere else I can check for additional firewalls? Would firewalls somehow impact ethernet and Wi-fi differently?  Inspect the network traffic or the router logs to see if and why the Mac DHCP broadcast packet is being ignored. How do I check network traffic on my Mac? I am comfortable using the terminal.   I have also tried steps listed as potential solutions in :   To reset the firewall, go to the /Macintosh HD/Library/Preferences/ folder and remove the file called "com.apple.alf.plist," and then restart your computer. On my computer I went to /Library/Preferences/ and ran sudo rm com.apple.alf.plist If that was already set, try the "Advanced" button, then "Renew DHCP Lease" Removing their "Ethernet" config from the Network settings and then re-adding   Does anyone have other suggestions? Thanks in advance Downloading PlayOnLinux I'm downloading PlayOnLinux to run Paint Tool SAI, but I cannot open PlayOnLinux. When I click on it to open it, a dialog box comes up that says: "PlayOnLinux cannot find curl (from cURL) You need to install it to continue". How do I install this?   I'm referring to this article: Zero-pad digits in string What is the relationship between Guide Number and flash power level? From this , I understand that the flash guide number (GN) is given by the following formula:  Guide Number = Shooting Distance × f-number ÷ ISO factor   I'm assuming that the GN calculated via the equation above will be based on a flash that is firing at full power. Am I correct to assume that if I set the flash to fire at half power, that the guide number is effectively halved? i.e. the equation will now be:  Guide Number = Shooting Distance × f-number ÷ ISO factor * Power Level   where power level can be the following 1, 1/2, 1/4, 1/8, ... 1/64, etc? Algorithm to see if two voxels are interconnected Isometric Embedding of a separable Banach Space into $\ell^{\infty}$ I found the question  Regarding the number of answers votes and also according to my personal taste I like to capitalize titles. But what exactly are titles? Only the single main book title? What about other smaller semantic parts? Chapter headings, sub-chapter, ... Why is `enjoy to [verb]` incorrect I can say:     I love to read. I hate to read.   But it must be:     I enjoy to read. I enjoy reading.   What is enjoy so different? Lightning component : Get the id of a record In a lightning component I display a list of articles (Article__c custom object) so I ca see, for example, the name of the article, the price, and a button that I'd like redirect to another component which display the details of the article selected.   For now I'm just trying to get the id of the article, in a basic alert in javascript, but I doesn't work : it says the id is null.   Here is a part of the component :  &lt;aura:handler name="init" value="{!this}" action="{!c.doInit}" /&gt; &lt;aura:attribute name="wrappers" type="ListeArticlesWrapper" /&gt; &lt;aura:attribute name="articles" type="Article__c" /&gt;  &lt;aura:attribute name="Detail" type="String"/&gt; &lt;aura:registerEvent name="navigate" type="c:NavigateToDetail"/&gt;  &lt;div class="page"&gt;     &lt;h1&gt;Liste des articles&lt;/h1&gt;     &lt;div class="slds"&gt;         &lt;table class="slds-table slds-table--bordered slds-table--cell-buffer"&gt;             &lt;thead&gt;                 &lt;tr class="slds-text-heading--label"&gt;                     &lt;th scope="col" class="head"&gt;&lt;/th&gt;                     &lt;th scope="col" class="head"&gt;Nom&lt;/th&gt;                     &lt;th scope="col" class="head"&gt;Type&lt;/th&gt;                     &lt;th scope="col" class="head"&gt;Prix&lt;/th&gt;                     &lt;th scope="col" class="head"&gt;&lt;/th&gt;                 &lt;/tr&gt;             &lt;/thead&gt;             &lt;tbody&gt;                 &lt;aura:iteration items="{!v.wrappers}" var="wrap"&gt;                     &lt;tr&gt;                         &lt;td class="cell"&gt;                             &lt;ui:inputCheckbox value="{!wrap.selected}" /&gt;                         &lt;/td&gt;                         &lt;td class="cell"&gt;                            &lt;ui:outputText value="{!wrap.art.Name}" /&gt;                         &lt;/td&gt;                         &lt;td class="cell"&gt;                             &lt;ui:outputText value="{!wrap.art.Type__c}" /&gt;                         &lt;/td&gt;                         &lt;td class="cell"&gt;                             &lt;ui:outputText value="{!wrap.art.Prix__c}" /&gt;                         &lt;/td&gt;                         &lt;td class="cell"&gt;                             &lt;button class="slds-button slds-button--neutral slds-not-selected"                                      onclick="{!c.getDetail}" data="{!wrap.art.Id}"&gt;Details&lt;/button&gt;                         &lt;/td&gt;                     &lt;/tr&gt;                 &lt;/aura:iteration&gt;             &lt;/tbody&gt;         &lt;/table&gt;   The associated controller js (with the function getDetail)  ({ doInit : function(component, event, helper) {     helper.init(component, event); },  getArticles : function(component, event, helper) {     helper.getArticles(component, event); },  getDetail : function(component, event, helper){     var id = event.target.getAttribute("data-data") || event.target.parentNode.getAttribute("data-data")     alert('detail article : id = ' + id); //it gives me null } })   Thanks !  EDIT  And the wrapper class in case you wonder what is the "art" :  public with sharing class ListeArticlesWrapper { //wrapper pour récupérer les articles selectionnés @AuraEnabled public Article__c art {get; set;}  @AuraEnabled public Boolean selected {get; set;} } How do I edit my profile? This is probably a noob question, but I forgot how to edit my profile.   Can anyone help me? There is no visible button for me. Should the eigenkets be weighted in $|P\rangle = \sum\limits_{r}|\xi^r\rangle$? Page 37 of Dirac's book The Principles of Quantum Mechanics, states  The condition for the eigenstates of $\xi$ to form a complete set must thus be formulated, that any ket $|P\rangle$ can be expressed as an integral plus a sum of eigenkets of $\xi$, i.e. $$|P\rangle = \int |\xi'c\rangle\; d\xi' + \sum\limits_{r}|\xi^rd\rangle$$ where the $|\xi'c\rangle$, $|\xi^rd\rangle$ are all eigenkets of $\xi$, the labels c and d being inserted to distinguish them when the eigenvalues $\xi'$ and $\xi^r$ are equal, and where the integral is taken over the whole range of eigenvalues and the sum is taken over any selection of them.  I find it inconsistent that the eigenkets under the integral are weighted by what appears to be a differential eigenvalue $d\xi'$, yet all the eigenkets under the summation are weighted by the value 1. Is this correct? To prove Cayley-Hamilton theorem, why can't we substitute $A$ for $\lambda$ in $p(\lambda) = \det(\lambda I - A)$? There exists an injection from $X$ to $Y$ if and only if there exists a surjection from $Y$ to $X$. Monotonicity of the sequences $\left(1+\frac1n\right)^n$, $\left(1-\frac1n\right)^n$ and $\left(1+\frac1n\right)^{n+1}$ Do people sometimes get blocked by a webservice for things someone else has done with their dynamic IP-Address It is common practice for operators of web services (e.g. web sites) to block IP addresses when there was malicious traffic originating from that address.  It is also common practice that internet users don't have a static IP address but get one assigned by their ISP via DHCP.  Now I would expect that it sometimes happens that a specific IP address gets banned from a service and later that address gets assigned to another user, leaving the new user (temporarily) banned from the service for no apparent reason. However, I never had this problem or heard of someone having that problem.  Does this sometimes happen? If not, what prevents this from happening? Why does the order in which libraries are linked sometimes cause errors in GCC? Why does the order in which libraries are linked sometimes cause errors in GCC? What does the symbol $\otimes$ mean?