大约有 44,000 项符合查询结果（耗时：0.1251秒） [XML]
Failure [INSTALL_FAILED_ALREADY_EXISTS] when I tried to update my application
...me here because I wanted to know whether adb install -r would remove first and then install or upgrade my app. Although adb's description is not very clear (-r: replace existing application), adb install -r does indeed upgrade your app and does not remove your app data. Therefore suitable to test up...
Why does Convert.ToString(null) return a different value if you cast null?
...e to any reference type. In this case string is more specific than object and hence it will be picked as the winner.
In the null as object you've solidified the type of the expression as object. This means it's no longer compatible with the string overload and the compiler picks the object over...
Assigning a variable NaN in python without numpy
...r all comparisons returning false for IEEE754 NaN values? for more details and information.
Instead, use math.isnan(...) if you need to determine if a value is NaN or not.
Furthermore, the exact semantics of the == operation on NaN value may cause subtle issues when trying to store NaN inside con...
How do I build a numpy array from a generator?
...ping this in mind, it is technically impossible to take a generator object and turn it into an array unless you either:
can predict how many elements it will yield when run:
my_array = numpy.empty(predict_length())
for i, el in enumerate(gimme()): my_array[i] = el
are willing to store its elemen...
How to generate an openSSL key using a passphrase from the command line?
...irst - what happens if I don't give a passphrase? Is some sort of pseudo random phrase used? I'm just looking for something "good enough" to keep casual hackers at bay.
...
Differences between Octave and MATLAB? [closed]
I'm a programmer who knows Python, Ruby and some C who is trying to decide whether to learn GNU Octave or Matlab. I know that they have a lot in common , but it isn't clear to me how similar the syntax is or even the data structures are. The above link shows several examples where they are syntacti...
What is the JavaScript convention for no operation?
...at is the JavaScript convention for no operation? Like a Python pass command.
6 Answers
...
Is there any way to use a numeric type as an object key?
...
@TimDown, and what I'm saying is that you are wrong. "Setting a numeric property on an Array can affect the length property" is an incorrect statement. Javascript Array properties are completely independent of Array elements. What conf...
Can local storage ever be considered secure? [closed]
... now reasonably well supported.
For an offline app, you must still design and implement a secure keystore.
Aside: If you are using Node.js, use the builtin crypto API.
Native-Javascript Cryptography (pre-WebCrypto)
I presume the primary concern is someone with physical access to the computer rea...
Bootstrap 3 breakpoints and media queries
... No media query since this is the default in Bootstrap
// Small devices (landscape phones, 576px and up)
@media (min-width: 576px) { ... }
// Medium devices (tablets, 768px and up)
@media (min-width: 768px) { ... }
// Large devices (desktops, 992px and up)
@media (min-width: 992px) { ... }
// Ex...