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Merge/flatten an array of arrays
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You can use concat to merge arrays:
var arrays = [
["$6"],
["$12"],
["$25"],
["$25"],
["$18"],
["$22"],
["$10"]
];
var merged = [].concat.apply([], arrays);
console.log(merged);
Using the apply metho...
What is the most efficient way to concatenate N arrays?
What is the most efficient way to concatenate N arrays of objects in JavaScript?
20 Answers
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MySQL CONCAT returns NULL if any field contain NULL
...nvert the NULL values with empty string by wrapping it in COALESCE
SELECT CONCAT(COALESCE(`affiliate_name`,''),'-',COALESCE(`model`,''),'-',COALESCE(`ip`,''),'-',COALESCE(`os_type`,''),'-',COALESCE(`os_version`,'')) AS device_name
FROM devices
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Best practices/performance: mixing StringBuilder.append with String.concat
I'm trying to understand what the best practice is and why for concatenating string literals and variables for different cases. For instance, if I have code like this
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How to concatenate and minify multiple CSS and JavaScript files with Grunt.js (0.3.x)
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concat.js is being included in the concat task's source files public/js/*.js. You could have a task that removes concat.js (if the file exists) before concatenating again, pass an array to explicitly define which files you wa...
How do I use the CONCAT function in SQL Server 2008 R2?
I was looking for a CONCAT function in SQL Server 2008 R2. I found the link for this function . But when I use this function, it gives the following error:
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How to concatenate columns in a Postgres SELECT?
...ing type columns like character(2) (as you mentioned later), the displayed concatenation just works because, quoting the manual:
[...] the string concatenation operator (||) accepts non-string
input, so long as at least one input is of a string type, as shown in
Table 9.8. For other cases, i...
Copy array items into another array
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Use the concat function, like so:
var arrayA = [1, 2];
var arrayB = [3, 4];
var newArray = arrayA.concat(arrayB);
The value of newArray will be [1, 2, 3, 4] (arrayA and arrayB remain unchanged; concat creates and returns a new arr...
IEnumerable to string [duplicate]
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You can use String.Concat().
var allowedString = String.Concat(
inputString.Where(c => allowedChars.Contains(c))
);
Caveat: This approach will have some performance implications. String.Concat doesn't special case collections of char...
Javascript Array Concat not working. Why?
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The concat method doesn't change the original array, you need to reassign it.
if ( ref instanceof Array )
this.refs = this.refs.concat( ref );
else
this.refs.push( ref );
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