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What should every developer know about databases? [closed]
Whether we like it or not, many if not most of us developers either regularly work with databases or may have to work with one someday. And considering the amount of misuse and abuse in the wild, and the volume of database-related questions that come up every day, it's fair to say that there are ce...
What does $.when.apply($, someArray) do?
...and Promises and keep coming across $.when.apply($, someArray) . I'm a little unclear on what this does exactly, looking for an explanation that one line works exactly (not the entire code snippet). Here's some context:
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What is the difference between == and Equals() for primitives in C#?
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Short answer:
Equality is complicated.
Detailed answer:
Primitives types override the base object.Equals(object) and return true if the boxed object is of the same type and value. (Note that it will also work for nullable types; non-null nullab...
How to set the prototype of a JavaScript object that has already been instantiated?
...have an object foo in my JavaScript code. foo is a complex object and it is generated somewhere else. How can I change the prototype of the foo object?
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notifyDataSetChanged example
...Application the notifyDataSetChanged() method for an ArrayAdapter but it doesn't work for me.
5 Answers
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Check if object exists in JavaScript
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You can safely use the typeof operator on undefined variables.
If it has been assigned any value, including null, typeof will return something other than undefined. typeof always returns a string.
Therefore
if (typeof maybeObject != "undefined") {
alert("GOT THERE");
}
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versionCode vs versionName in Android Manifest
I had my app in the android market with version code = 2 and version name = 1.1
10 Answers
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What is the difference between a function expression vs declaration in JavaScript? [duplicate]
...hes that line of code.
So if you try to call a function expression before it's loaded, you'll get an error! If you call a function declaration instead, it'll always work, because no code can be called until all declarations are loaded.
Example: Function Expression
alert(foo()); // ERROR! foo was...
Detecting an undefined object property
...ty, and will therefore return undefined by default when you try and access it:
if(!o.hasOwnProperty('myProperty')) {
alert("myProperty does not exist");
}
To check if the value associated with an identifier is the special value undefined, or if that identifier has not been declared. Note: this ...
What does “connection reset by peer” mean?
...he meaning of the "connection reset by peer" error on a TCP connection? Is it a fatal error or just a notification or related to the network failure?
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