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“INSERT IGNORE” vs “INSERT … ON DUPLICATE KEY UPDATE”
...th many rows, I want to skip duplicate entries that would otherwise cause failure. After some research, my options appear to be the use of either:
...
Create objective-c class instance by name?
...utilize the Objective-C language runtime library's API. Under Objective-C 2.0:
#import <objc/runtime.h>
//Declaration in the above named file
id objc_getClass(const char* name);
//Usage
id c = objc_getClass("Object");
[ [ c alloc ] free ];
Under the Objective-C (1.0 or unnamed version) you...
Android Center text on canvas
...t() - mPaint.ascent();
bounds.left += (r.width() - bounds.right) / 2.0f;
bounds.top += (r.height() - bounds.bottom) / 2.0f;
yourCanvas.drawText(pageTitle, bounds.left, bounds.top - mPaint.ascent(), mPaint);
}
@Override
protected void onSizeChanged(int w, int h, i...
Need for predictable random generator
...ndomness in small runs of some games is undesirable -- it does seem too unfair for some use cases.
I wrote a simple Shuffle Bag like implementation in Ruby and did some testing. The implementation did this:
If it still seems fair or we haven't reached a threshold of minimum rolls, it returns a...
What is the difference between float and double?
... + 3.9999999 = 0, the exact roots to 10 significant digits are, r1 = 2.000316228 and r2 = 1.999683772.
Using float and double, we can write a test program:
#include <stdio.h>
#include <math.h>
void dbl_solve(double a, double b, double c)
{
double d = b*b - 4.0*a*c;
dou...
When to encode space to plus (+) or %20?
...www-form-urlencoded'. This is used for posting form data.
Now, the HTML 2.0 Specification (RFC1866) explicitly said, in section 8.2.2, that the Query part of a GET request's URL string should be encoded as 'application/x-www-form-urlencoded'. This, in theory, suggests that it's legal to use a '...
What is the C++ function to raise a number to a power?
...yped so it matches one of those three perfectly. I usually use double
pow(2.0, N)
Some lawyer crap from me again. I've often fallen in this pitfall myself, so I'm going to warn you about it.
share
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Log to the base 2 in python
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float → float math.log2(x)
import math
log2 = math.log(x, 2.0)
log2 = math.log2(x) # python 3.4 or later
Thanks @akashchandrakar and @unutbu.
float → int math.frexp(x)
If all you need is the integer part of log base 2 of a floating point number, extracting the exponent i...
IOS: create a UIImage or UIImageView with rounded corners
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I have used this code in Swift 2.0, and it worked properly, thank you. By the way, I have changed YES by true.
– lmiguelvargasf
Aug 19 '15 at 17:31
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How to generate the JPA entity Metamodel?
In the spirit of type safety associated with the CriteriaQuery JPA 2.0 also has an API to support Metamodel representation of entities.
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