大约有 45,000 项符合查询结果（耗时：0.0638秒） [XML]
Why does this loop produce “warning: iteration 3u invokes undefined behavior” and output more than 4
...in seeing this code:
struct foo *s = ...;
int x = s->f;
if (!s) return ERROR;
gcc inferred that since s was deferenced in s->f; and since dereferencing a null pointer is undefined behavior then s must not be null and therefore optimizes away the if (!s) check on the next line.
The lesson ...
How to prevent robots from automatically filling up a form?
...script first using a noscript statement:
<noscript>
<p class="error">
ERROR: The form could not be loaded. Please enable JavaScript in your browser to fully enjoy our services.
</p>
</noscript>
Create a form.html and place your form inside a <div id="formConta...
Difference between const & const volatile
...rked as const volatile will not be permitted to be changed by the code (an error will be raised due to the const qualifier) - at least through that particular name/pointer.
The volatile part of the qualifier means that the compiler cannot optimize or reorder access to the object.
In an embedded sy...
Check if a variable is a string in JavaScript
...vides "defensiveness" against issues that will blow up your js app. Fatal errors happen when you attempt to do string operations on an object (or vice versa), and Lodash provides tremendous value around preventing those errors.
– random_user_name
Oct 17 '17 at...
What is the difference between typeof and instanceof and when should one be used vs. the other?
... Use instanceof for complex built in types - this is still prone to error. Better to use ES5 Array.isArray() et al. or the recommended shims.
– OrangeDog
May 4 '16 at 11:27
...
How do I make JavaScript beep?
...
I get TypeError: sound.Play is not a function (in Firefox).
– ashleedawg
Feb 18 '19 at 12:51
3
...
Getting the last element of a list
...list
[1, 3, 5]
Note that getting a list item by index will raise an IndexError if the expected item doesn't exist. This means that some_list[-1] will raise an exception if some_list is empty, because an empty list can't have a last element.
...
How to change Git log date formats
...nd it, please comment) so I originally found the placeholders by trial and error.
In my search for documentation on this I found a commit to Git itself that indicates the format is fed directly to strftime. Looking up strftime (here or here) the placeholders I found match the placeholders listed.
Th...
Pass data to layout that are common to all pages
...
Perfect! I saw my error. I forgot to pass the model to the view.. what a lame error. Thanks!
– Rushino
Nov 5 '12 at 23:35
7...
Force update of an Android app when a new version is available
...ion)){
if(!isFinishing()){ //This would help to prevent Error : BinderProxy@45d459c0 is not valid; is your activity running? error
showUpdateDialog();
}
}
}
else
background.start();
...