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How to determine whether an object has a given property in JavaScript
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Or even better — Object.prototype.hasOwnProperty.call(x, 'y'), so that property named "hasOwnProperty" would not conflict with inspection process ;)
– kangax
Dec 24 '09 at 14:03
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Difference between attr_accessor and attr_accessible
...o submit a new salary to the controller update method, they could create a script that submits a post with that information.
So attr_accessor is about creating methods to store variables, and attr_accessible is about the security of mass assignments.
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What is a bus error?
... when your processor cannot even attempt the memory access requested, typically:
using a processor instruction with an address that does not satisfy its alignment requirements.
Segmentation faults occur when accessing memory which does not belong to your process, they are very common and are typ...
JOIN queries vs multiple queries
...ponential memory leak issue. Grab all of the data, then use a server-side scripting language to sort it out:
SELECT * FROM Address WHERE Personid IN(1,2,3);
Results:
Address.id : 1 // First person and their address
Address.Personid : 1
Address.City : "Boston"
Address.id : 2 ...
“User interaction is not allowed” trying to sign an OSX app using codesign
...design through ssh without actually storing the login password inside some script?
– chakrit
Aug 31 '14 at 16:35
2
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How to check if a variable is a dictionary in Python?
...t, defaultdict, or Counter from the collections module:
if isinstance(any_object, dict):
But there are even more flexible options.
Supporting abstractions:
from collections.abc import Mapping
if isinstance(any_object, Mapping):
This allows the user of your code to use their own custom implem...
Converting NSString to NSDate (and back again)
...String = @"01-02-2010";
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"dd-MM-yyyy"];
NSDate *dateFromString = [dateFormatter dateFromString:dateString];
NSDate convert to NSString:
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[d...
How do you work with an array of jQuery Deferreds?
...when.all() method that addresses these problems:
// Put somewhere in your scripting environment
if (jQuery.when.all===undefined) {
jQuery.when.all = function(deferreds) {
var deferred = new jQuery.Deferred();
$.when.apply(jQuery, deferreds).then(
function() {
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How to prevent buttons from submitting forms
...bmit and handling the event server-side - this is known as unobtrusive JavaScript.
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Is null reference possible?
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References are not pointers.
8.3.2/1:
A reference shall be initialized to
refer to a valid object or function.
[Note: in particular, a null reference
cannot exist in a well-defined
program, because the only way to
create such a reference would be to
bind it to the ...