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What is the difference between the template method and the strategy patterns?
...atum); }
}
In summary:
Template method pattern: compile-time algorithm selection by subclassing
Strategy pattern: run-time algorithm selection by containment
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Regular expression to match DNS hostname or IP Address?
...check separately that the total length of the hostname must not exceed 255 characters. For more information, please consult RFC-952 and RFC-1123.
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How to display Base64 images in HTML?
...e. See this fiddle where similar scheme is working. You may try specifying char set.
<div>
<p>Taken from wikpedia</p>
<img src="data:image/png;base64, iVBORw0KGgoAAAANSUhEUgAAAAUA
AAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO
9TXL0Y4OHwAAA...
contenteditable, set caret at the end of the text (cross-browser)
...
function placeCaretAtEnd(el) {
el.focus();
if (typeof window.getSelection != "undefined"
&& typeof document.createRange != "undefined") {
var range = document.createRange();
range.selectNodeContents(el);
range.collapse(false);
var s...
In PHP what does it mean by a function being binary-safe?
...on which expects null-terminated strings, so if the string contains a null character, the function would ignore anything after it.
This is relevant because PHP does not cleanly separate string and binary data.
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“Insert if not exists” statement in SQLite
... and text you should be able to do like this:
INSERT INTO memos(id,text)
SELECT 5, 'text to insert'
WHERE NOT EXISTS(SELECT 1 FROM memos WHERE id = 5 AND text = 'text to insert');
If a record already contains a row where text is equal to 'text to insert' and id is equal to 5, then the insert op...
Convert file path to a file URI?
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Nor will this work with paths that contain a # character.
– lewis
Feb 24 at 15:28
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How to drop a table if it exists?
...
Is it correct to do the following?
IF EXISTS(SELECT *
FROM dbo.Scores)
DROP TABLE dbo.Scores
No. That will drop the table only if it contains any rows (and will raise an error if the table does not exist).
Instead, for a permanent table you can use
I...
How to get the max of two values in MySQL?
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Use GREATEST()
E.g.:
SELECT GREATEST(2,1);
Note: Whenever if any single value contains null at that time this function always returns null (Thanks to user @sanghavi7)
s...
Is there a better way to express nested namespaces in C++ within the header
...A_HELPER_EXPAND(VA_COUNT_HELPER(__VA_ARGS__, 6, 5, 4, 3, 2, 1))
#define VA_SELECT_CAT(_Name, _Count, ...) VA_HELPER_EXPAND(_Name##_Count(__VA_ARGS__))
#define VA_SELECT_HELPER(_Name, _Count, ...) VA_SELECT_CAT(_Name, _Count, __VA_ARGS__)
#define VA_SELECT(_Name, ...) VA_SE...