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What is the difference between ${var}, “$var”, and “${var}” in the Bash shell?
...happen in a particular order, and some have specific use cases.
Braces as Token Delimiters
The ${var} syntax is primarily used for delimiting ambiguous tokens. For example, consider the following:
$ var1=foo; var2=bar; var12=12
$ echo $var12
12
$ echo ${var1}2
foo2
Braces in Array Expansions
T...
#ifdef vs #if - which is better/safer as a method for enabling/disabling compilation of particular s
...rather than 0/1 in your #define, and because the value is a single lexical token, it's the one time you don't need parentheses around it.
#define DEBUG_ENABLED true
instead of
#define DEBUG_ENABLED (1)
share
...
Python List vs. Array - when to use?
...discontiguous and sparse arrays, and I think some pluggable strategies for allocating memory for large arrays... some of these advanced features will make it user less memory, while others will improve performance by using more memory.
– Dan Lenski
Oct 29 '14 a...
Java heap terminology: young, old and permanent generations?
...lowing.
Eden Space (heap): The pool from which memory is initially allocated
for most objects.
Survivor Space (heap): The pool containing objects that have survived
the garbage collection of the Eden
space.
Tenured Generation (heap): The pool containing objects that have existed
...
How do you do Impersonation in .NET?
...nerally use WindowsIdentity.RunImpersonated, which accepts a handle to the token of the user account, and then either an Action or Func<T> for the code to execute.
WindowsIdentity.RunImpersonated(tokenHandle, () =>
{
// do whatever you want as this user.
});
or
var result = WindowsI...
How to avoid reverse engineering of an APK file?
...ecure channel were compromised.
Once verified, the server transmits back a token over the channel. The token is only useful within the secure session, is composed of either random noise or an encrypted (and thus verifiable) copy of the session identifiers, and the client application must send this t...
Is Java really slow?
...bandwidth bound (caching, etc.) this makes it slower. The flipside is that allocation/deallocation is blazing fast (highly optimized). This is a feature of most high-level languages now, and due to objects and use of GC rather than explicit memory allocation. Plus bad library decisions.
Streams-bas...
UITextfield leftView/rightView padding on iOS7
...:UITextFieldViewModeUnlessEditing];
self.leftView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"textfield_edit_icon.png"]];
}
return self;
}
You may have to import #import <QuartzCore/QuartzCore.h>
Add the rightViewRectForBounds method above
In Interface Builder...
How to make sure that string is valid JSON using JSON.NET
...method).
(Using JSON.Net)
Simplest way would be to Parse the string using JToken.Parse, and also to check if the string starts with { or [ and ends with } or ] respectively (added from this answer):
private static bool IsValidJson(string strInput)
{
if (string.IsNullOrWhiteSpace(strInput)) { ret...
Make Https call using HttpClient
....github.com");
client.DefaultRequestHeaders.Add(
"Authorization",
"token 123456789307d8c1d138ddb0848ede028ed30567");
client.DefaultRequestHeaders.Accept.Add(
new MediaTypeWithQualityHeaderValue("application/json"));
client.DefaultRequestHeaders.Add(
"User-Agent",
"Mozilla/5.0 (Wi...