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How do I check to see if a value is an integer in MySQL?
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I'll assume you want to check a string value. One nice way is the REGEXP operator, matching the string to a regular expression. Simply do
select field from table where field REGEXP '^-?[0-9]+$';
this is reasonably fast. If your field is numeric, just tes...
Merge/flatten an array of arrays
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Ahh, I found your error. You have an extra pair of square brackets in your notation, should be [].concat([1],[2,3],[4],...).
– Ryan Kennedy
Aug 6 '13 at 15:27
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How to get URL of current page in PHP [duplicate]
..._SERVER array, see the PHP manual page for it.
If you also need the query string (the bit after the ? in a URL), that part is in this variable:
$_SERVER['QUERY_STRING']
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Last iteration of enhanced for loop in java
...n't use "" + i, by the way - you don't really want concatenation here, and StringBuilder has a perfectly good append(int) overload.)
int[] array = {1, 2, 3...};
StringBuilder builder = new StringBuilder();
for (int i : array) {
if (builder.length() != 0) {
builder.append(",");
}
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How can I sanitize user input with PHP?
...at you should do, to avoid problems, is quite simple: whenever you embed a string within foreign code, you must escape it, according to the rules of that language. For example, if you embed a string in some SQL targeting MySQL, you must escape the string with MySQL's function for this purpose (mysql...
How to get the name of enumeration value in Swift?
... print type names and enum cases by default using print(_:), or convert to String using String's init(_:) initializer or string interpolation syntax. So for your example:
enum City: Int {
case Melbourne = 1, Chelyabinsk, Bursa
}
let city = City.Melbourne
print(city)
// prints "Melbourne"
let ...
Escape double quotes in a string
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No.
Either use verbatim string literals as you have, or escape the " using backslash.
string test = "He said to me, \"Hello World\" . How are you?";
The string has not changed in either case - there is a single escaped " in it. This is just a way...
How do I check if a string is valid JSON in Python?
In Python, is there a way to check if a string is valid JSON before trying to parse it?
4 Answers
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JavaScript window resize event
... removing event listeners, but in the case that you don't, adding all that extra code like in the example above is unnecessary and can both to bloat and less readability. In my opinion, if you don't envision a reason to need to remove the listener, this approach is the best solution. You can always ...
When do we need curly braces around shell variables?
...er, the {} in ${} are useful if you want to expand the variable foo in the string
"${foo}bar"
since "$foobar" would instead expand the variable identified by foobar.
Curly braces are also unconditionally required when:
expanding array elements, as in ${array[42]}
using parameter expansion oper...