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Email Address Validation in Android on EditText [duplicate]
How can we perform Email Validation on edittext in android ? I have gone through google & SO but I didn't find out a simple way to validate it.
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Apply a function to every row of a matrix or a data frame
Suppose I have a n by 2 matrix and a function that takes a 2-vector as one of its arguments. I would like to apply the function to each row of the matrix and get a n-vector. How to do this in R?
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Gray out image with CSS?
What's the best way (if any) to make an image appear "grayed out" with CSS (i.e., without loading a separate, grayed out version of the image)?
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How do you push a Git tag to a branch using a refspec?
I want to force push, for example, my tag 1.0.0 to my remote master branch.
4 Answers
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Semi-transparent color layer over background-image?
I have a DIV and I would like to put a pattern as background. This pattern is gray. So to make it a little more nice, I would like to put a light transparent color "layer" over. Below is what I tried but which did not work. Is there a way to put the colored layer over the background image?
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Converting RGB to grayscale/intensity
When converting from RGB to grayscale, it is said that specific weights to channels R, G, and B ought to be applied. These weights are: 0.2989, 0.5870, 0.1140.
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remove None value from a list without removing the 0 value
This was my source I started with.
10 Answers
10
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What's the (hidden) cost of Scala's lazy val?
One handy feature of Scala is lazy val , where the evaluation of a val is delayed until it's necessary (at first access).
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Reset C int array to zero : the fastest way?
Assuming that we have a T myarray[100] with T = int, unsigned int, long long int or unsigned long long int, what is the fastest way to reset all its content to zero (not only for initialization but to reset the content several times in my program)? Maybe with memset?
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Why is XOR the default way to combine hashes?
Say you have two hashes H(A) and H(B) and you want to combine them. I've read that a good way to combine two hashes is to XOR them, e.g. XOR( H(A), H(B) ) .
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