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How to check file MIME type with javascript before upload?
...emo at the bottom.
Check that your browser supports both File and Blob. All major ones should.
if (window.FileReader && window.Blob) {
// All the File APIs are supported.
} else {
// File and Blob are not supported
}
Step 1:
You can retrieve the File information from an <in...
Join strings with a delimiter only if strings are not null or empty
...
.filter(Boolean) (which is the same as .filter(x => x)) removes all "falsy" values (nulls, undefineds, empty strings etc). If your definition of "empty" is different, then you'll have to provide it, for example:
[...].filter(x => typeof x === 'string' && x.length > 0)
wi...
Empty arrays seem to equal true and false at the same time
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You're testing different things here.
if (arr) called on object (Array is instance of Object in JS) will check if the object is present, and returns true/false.
When you call if (arr == false) you compare values of this object and the primitive false value. Internally, a...
What is the difference between ELF files and bin files?
...ded loader format ELf file ,what is the difference between the two , especially the utility of ELF file.
4 Answers
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Replace selector images programmatically
...that has a drawable image resource set to a selector. How do I programmatically access the selector and change the images of the highlighted and non-highlighted state?
...
Where is the “Fold” LINQ Extension Method?
I found in MSDN's Linq samples a neat method called Fold() that I want to use. Their example:
2 Answers
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Why is char[] preferred over String for passwords?
... believe this is implementation-specific - the garbage collector may clear all memory as it goes, to avoid this sort of thing. Even if it does, there's still the time during which the char[] contains the actual characters as an attack window.
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How to avoid passing parameters everywhere in play2?
In play1, I usually get all data in actions, use them directly in views. Since we don't need to explicitly declare parameters in view, this is very easy.
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How to do a scatter plot with empty circles in Python?
... colored disks already plotted by scatter() , so as to highlight them, ideally without having to redraw the colored circles.
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How to delete a row by reference in data.table?
...nce yet.
data.table can add and delete columns by reference since it over-allocates the vector of column pointers, as you know. The plan is to do something similar for rows and allow fast insert and delete. A row delete would use memmove in C to budge up the items (in each and every column) after t...