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Use of 'prototype' vs. 'this' in JavaScript?
...e [[Prototype]] property.
A function's this is set by how the function is called or by the use of bind (not discussed here). Where a function is called on an object (e.g. myObj.method()) then this within the method references the object. Where this is not set by the call or by the use of bind, it de...
Efficient way to apply multiple filters to pandas DataFrame or Series
...s to apply several filters to a Pandas DataFrame or Series object. Essentially, I want to efficiently chain a bunch of filtering (comparison operations) together that are specified at run-time by the user.
...
Assignment inside lambda expression in Python
I have a list of objects and I want to remove all objects that are empty except for one, using filter and a lambda expression.
...
The following sections have been defined but have not been rendered for the layout page “~/Views/Sha
... _Layout.cshtml has something like this:
@RenderSection("scripts")
Then all Views that use that Layout must include a @section with the same name (even if the contents of the section are empty):
@{
ViewBag.Title = "Title";
Layout = "~/Views/Shared/_Layout.cshtml";
}
@section scripts{
...
How can I add a key/value pair to a JavaScript object?
... property. The second form is used when the name of the property is dynamically determined. Like in this example:
var getProperty = function (propertyName) {
return obj[propertyName];
};
getProperty("key1");
getProperty("key2");
getProperty("key3");
A real JavaScript array can be construct...
How to allocate aligned memory only using the standard library?
...
Original answer
{
void *mem = malloc(1024+16);
void *ptr = ((char *)mem+16) & ~ 0x0F;
memset_16aligned(ptr, 0, 1024);
free(mem);
}
Fixed answer
{
void *mem = malloc(1024+15);
void *ptr = ((uintptr_t)mem+15) & ~ (uintptr_t)0x0...
Read-only and non-computed variable properties in Swift
...g in Objective-C. I have readonly properties, and they cannot be individually changed. However, using a specific method, the properties are changed in a logical way.
...
When do we need curly braces around shell variables?
...xpand the variable identified by foobar.
Curly braces are also unconditionally required when:
expanding array elements, as in ${array[42]}
using parameter expansion operations, as in ${filename%.*} (remove extension)
expanding positional parameters beyond 9: "$8 $9 ${10} ${11}"
Doing this every...
How can I hash a password in Java?
...
You can actually use a facility built in to the Java runtime to do this. The SunJCE in Java 6 supports PBKDF2, which is a good algorithm to use for password hashing.
byte[] salt = new byte[16];
random.nextBytes(salt);
KeySpec spec = new...
What techniques can be used to speed up C++ compilation times?
...ity that takes advantage of caching techniques to speed things up.
Use Parallelism
Many compilers / IDEs support using multiple cores/CPUs to do compilation simultaneously. In GNU Make (usually used with GCC), use the -j [N] option. In Visual Studio, there's an option under preferences to allow it...