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JPA getSingleResult() or null
...n it doesn't exist or update it if it does. To enable this, I have to findByIdAndForeignKey , if it returned null insert if not then update. The problem is how do I check if it exists? So I tried getSingleResult . But it throws an exception if the
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Is PHP's count() function O(1) or O(n) for arrays?
...ng: PHP Count Performance. Although the length of the array is maintained by the array, it still seems as though it is faster to hold on to it if you are going to call count() many times.
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Is onload equal to readyState==4 in XMLHttpRequest?
...t URLs and see the actual sequence of events and readyState values as seen by the JavaScript app in different cases. The JS code is also listed below:
var xhr;
function test(url) {
xhr = new XMLHttpRequest();
xhr.addEventListener("readystatechange", function() { log(xhr, "readystatechange")...
convert a JavaScript string variable to decimal/money
...
Yes -- parseFloat.
parseFloat(document.getElementById(amtid4).innerHTML);
For formatting numbers, use toFixed:
var num = parseFloat(document.getElementById(amtid4).innerHTML).toFixed(2);
num is now a string with the number formatted with two decimal places.
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How to find out which JavaScript events fired?
... the right).
You can also view all events that have already been attached by simply right clicking on the element and then browsing its properties (the panel on the right).
For example:
Right click on the upvote button to the left
Select inspect element
Collapse the styles section (section on the...
How do you represent a JSON array of strings?
...an array:
[value, value]
Hint: spaces among elements are always ignored by any JSON parser.
And value is an object, array, string, number, bool or null:
So yeah, ["a", "b"] is a perfectly valid JSON, like you could try on the link Manish pointed.
Here are a few extra valid JSON examples, one pe...
Android Task Affinity Explanation
...VITY_NEW_TASK, the activity is then put into this particular task (defined by taskAffinity).
– Stan Mots
Jan 14 '17 at 16:42
3
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Is there any way to not return something using CoffeeScript?
...ot accidentally returning the results of the comprehension in these cases, by adding a meaningful return value — like true — or null, to the bottom of your function.
You could, however, write a wrapper like this:
voidFun = (fun) ->
->
fun(arguments...)
return
(No...
Is the 'type' attribute necessary for tags?
...o the JavaScript Script top-level production. Classic scripts are affected by the charset, async, and defer attributes. Authors should omit the attribute, instead of redundantly giving a JavaScript MIME type.
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redirect COPY of stdout to log file from within bash script itself
...g file would not contain any error messages.
# SEE (and upvote) the answer by Adam Spiers, which keeps STDERR
# as a separate stream - I did not want to steal from him by simply
# adding his answer to mine.
exec 2>&1
echo "foo"
echo "bar" >&2
Note that this is bash, not sh. If you i...