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How to avoid long nesting of asynchronous functions in Node.js
...lback(null, 'three');
},
function(arg1, callback){
// arg1 now equals 'three'
callback(null, 'done');
}
], function (err, result) {
// result now equals 'done'
});
As for the req,res variables, they will be shared within the same scope as function(req,res){} whi...
Awaiting multiple Tasks with different results
...eTask;
var car = await carTask;
You can also use Task.Result (since you know by this point they have all completed successfully). However, I recommend using await because it's clearly correct, while Result can cause problems in other scenarios.
...
Select first row in each GROUP BY group?
...ndex-only scans is in development for Postgres 14. See here and here.)
For now, there are faster query techniques to substitute for this. In particular if you have a separate table holding unique customers, which is the typical use case. But also if you don't:
Optimize GROUP BY query to retrieve la...
What is “rvalue reference for *this”?
...n"; }
};
int main(){
test t;
t.f(); // OK
test().f(); // OK too
}
Now, onto why @Nicol's answer is atleast partly wrong. He says:
Note that this declaration changes the type of *this.
That is wrong, *this is always an lvalue:
§5.3.1 [expr.unary.op] p1
The unary * operator performs indir...
How to create a file in Ruby
...
OK, now I feel stupid. The first two definitely do not work but the second two do. Not sure how I convinced my self that I had tried them. Sorry for wasting everyone's time.
In case this helps anyone else, this can occur when y...
How can I read input from the console using the Scanner class in Java?
...
This is now a better, more up to date answer than the original one imo.
– logicOnAbstractions
Mar 26 '18 at 16:00
...
When to use std::size_t?
...odel size or index in an array. size_t conveys semantics: you immediately know it represents a size in bytes or an index, rather than just another integer.
Also, using size_t to represent a size in bytes helps making the code portable.
...
Unable to set data attribute using jQuery Data() API
...', 'yoda')", ".data('key')", "expect leia (still) on jQuery object but DOM now yoda");
logger("", ".attr('key')", "expect undefined (no attr <code>key</code>)");
logger("", ".attr('data-key')", "expect yoda in DOM and on jQuery object");
// bonus points
logger('', ".data...
How can I confirm a database is Oracle & what version it is using SQL?
...
@Prokhozhii - We now use 19 so i can no longer confirm but I would appreciate it if you could provide additional explanation as select version from v$instance definitely works in Oracle 11 . See answer
What’s the best way to reload / refresh an iframe?
...to reload an <iframe> using JavaScript. The best way I found until now was set the iframe’s src attribute to itself, but this isn’t very clean. Any ideas?
...