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How to check if array element exists or not in javascript?
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Use typeof arrayName[index] === 'undefined'
i.e.
if(typeof arrayName[index] === 'undefined') {
// does not exist
}
else {
// does exist
}
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How do I store data in local storage using Angularjs?
Currently I am using a service to perform an action, namely
retrieve data from the server and then store the data on the server itself.
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Difference between “!==” and “==!” [closed]
Yesterday I stumbled over this when I modified PHP code written by someone else. I was baffled that a simple comparison ( if ($var ==! " ") ) didn't work as expected. After some testing I realized that whoever wrote that code used ==! instead of !== as comparison operator. I've never seen ==! ...
Map over object preserving keys
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it looks to me like you're making an OBJECT into an object, or am i out of my mind?
– jsh
Sep 28 '15 at 18:22
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lodash multi-column sortBy descending
There's a nifty method to sort an array of objects based on several properties:
7 Answers
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How can I recall the argument of the previous bash command?
Is there a way in Bash to recall the argument of the previous command?
7 Answers
7
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PowerShell equivalent to grep -f
I'm looking for the PowerShell equivalent to grep --file=filename . If you don't know grep , filename is a text file where each line has a regular expression pattern you want to match.
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jQuery get values of checked checkboxes into array
...t the very end to turn the resulting jQuery object into a true array.
$("#merge_button").click(function(event){
event.preventDefault();
var searchIDs = $("#find-table input:checkbox:checked").map(function(){
return $(this).val();
}).get(); // <----
console.log(searchIDs);
}...
Get: TypeError: 'dict_values' object does not support indexing when using python 3.2.3 [duplicate]
...t.keys() and dict.items()) returns a view, rather than a list. See the documentation here. You therefore need to wrap your call to dict.values() in a call to list like so:
v = list(d.values())
{names[i]:v[i] for i in range(len(names))}
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Is there shorthand for returning a default value if None in Python? [duplicate]
In C#, I can say x ?? "" , which will give me x if x is not null, and the empty string if x is null. I've found it useful for working with databases.
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