大约有 44,000 项符合查询结果（耗时：0.0570秒） [XML]
Check if a user has scrolled to the bottom
...he .scroll() event on window, like this:
$(window).scroll(function() {
if($(window).scrollTop() + $(window).height() == $(document).height()) {
alert("bottom!");
}
});
You can test it here, this takes the top scroll of the window, so how much it's scrolled down, adds the height of th...
Create a folder if it doesn't already exist
...
Try this, using mkdir:
if (!file_exists('path/to/directory')) {
mkdir('path/to/directory', 0777, true);
}
Note that 0777 is already the default mode for directories and may still be modified by the current umask.
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How to tell if a tag failed to load
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The "onload" listener will be fired even if there's a javascript error.
– Luca Matteis
Feb 11 '09 at 21:38
38
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If isset $_POST
I have a form on one page that submits to another page. There, it checks if the input mail is filled. If so then do something and if it is not filled, do something else. I don't understand why it always says that it is set, even if I send an empty form. What is missing or wrong?
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Error in if/while (condition) {: missing Value where TRUE/FALSE needed
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The evaluation of condition resulted in an NA. The if conditional must have either a TRUE or FALSE result.
if (NA) {}
## Error in if (NA) { : missing value where TRUE/FALSE needed
This can happen accidentally as the results of calculations:
if(TRUE && sqrt(-1)) ...
Assign variable value inside if-statement [duplicate]
...can be assigned but not declared inside the conditional statement:
int v;
if((v = someMethod()) != 0) return true;
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Check if string contains only whitespace
How can I test if a string contains only whitespace?
11 Answers
11
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Android: how to check if a View inside of ScrollView is visible?
...ew which holds a series of Views . I would like to be able to determine if a view is currently visible (if any part of it is currently displayed by the ScrollView ). I would expect the below code to do this, surprisingly it does not:
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How can i tell if an object has a key value observer attached
if you tell an objective c object to removeObservers: for a key path and that key path has not been registered, it cracks the sads. like -
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Check if a program exists from a Makefile
How can I check if a program is callable from a Makefile?
12 Answers
12
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