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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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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...
Increment value in mysql update query
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Concatenating user data as demonstrated into an SQL query is a major SQL injection risk.
– trognanders
Nov 6 '15 at 1:20
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How can I combine multiple rows into a comma-delimited list in Oracle? [duplicate]
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Just make sure your concatenated results don't exceed the VARCHAR2 max length limit of your oracle database (most likely 4000 bytes) otherwise you will run into ORA-01489 result of string concatenation is too long.
– JanM
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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 flatten tree via LINQ?
...rable<MyNode> e) =>
e.SelectMany(c => Flatten(c.Elements)).Concat(new[] { e });
You can then filter by group using Where(...).
To earn some "points for style", convert Flatten to an extension function in a static class.
public static IEnumerable<MyNode> Flatten(this IEnumer...
Create JSON object dynamically via JavaScript (Without concate strings)
...estions%2f16507222%2fcreate-json-object-dynamically-via-javascript-without-concate-strings%23new-answer', 'question_page');
}
);
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In MySQL, can I copy one row to insert into the same table?
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SET @temptable = '_duplicate_temp_table';
SET @sql_text = CONCAT('CREATE TABLE ', @temptable, ' LIKE ', copytable);
PREPARE stmt FROM @sql_text;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
SET @sql_text = CONCAT('INSERT INTO ', @temptable, ' SELECT * FROM ...
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...
XDocument.ToString() drops XML Encoding Tag
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use this:
output.Text = String.Concat(xml.Declaration.ToString() , xml.ToString())
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