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Why is the default value of the string type null instead of an empty string?
... the behaviour of reference types. Before invoking their instance members, one should put a check in place for a null reference.
If the default value of string were the empty string, I would not have
to test, and I would feel it to be more consistent with the other
value types like int or do...
subtle differences between JavaScript and Lua [closed]
...arison operators. In JS, only === and !== don't type juggle.
Lua has an exponentiation operator (^); JS doesn't. JS uses different operators, including the ternary conditional operator (?: vs and/or), and, as of 5.3, bitwise operators (&, |, etc. vs. metamethods ).
UPDATE: JS now has the expon...
What does “Memory allocated at compile time” really mean?
...itial- ization takes place. In some
cases, additional initialization is done later.
I always suggest people to disassembly their code to see what the compiler really does with the C++ code. This applies from storage classes/duration (like this question) to advanced compiler optimizations. You co...
Execute code when Django starts ONCE only?
... hook for this
Don't do it this way.
You don't want "middleware" for a one-time startup thing.
You want to execute code in the top-level urls.py. That module is imported and executed once.
urls.py
from django.confs.urls.defaults import *
from my_app import one_time_startup
urlpatterns = ......
How to implement a queue using two stacks?
...uct a queue using two stacks.
Our queue model will consist of two stacks. One stack will be used for enqueue operation (stack #1 on the left, will be called as Input Stack), another stack will be used for the dequeue operation (stack #2 on the right, will be called as Output Stack). Check out the i...
How to set time delay in javascript
...var tid = setInterval(function(){
//called 5 times each time after one second
//before getting cleared by below timeout.
alert("I am setInterval");
},1000); //delay is in milliseconds
alert("after setInterval"); //called second
setTimeout(function(){
clearInterv...
How to move Jenkins from one PC to another
...
Got the solution to my problem mentioned in my previous comment: Goto Manage Jenkins > configure system. Here in section 'Jenkins Location', under 'Jenkins URL' field, change the URL to point it to new jenkins server.
– merlachandra
...
What are the uses for Cross Join?
...g very practical if you were given 2 sets of id's (perhaps in csv format), one set would contain the employee ids and the other would contain task ids. The idea is that you have a M2M table for EmployeeTask. You could use the cross join to assign every given task to every given employee, granted you...
How do I upload a file with metadata using a REST web service?
...
One advantage to sending the content first is that by the time the metadata exists, the content is already present. Ultimately the right answer depends on the organisation of the data in the system.
– Gr...
What is an Intent in Android?
... a messaging object you can use to request an action from another app component
An Intent is basically a message to say you did or want something to happen. Depending on the intent, apps or the OS might be listening for it and will react accordingly. Think of it as a blast email to a bunch of fri...