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How to check internet access on Android? InetAddress never times out
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- does not work on some old devices (Galays S3, etc.), it blocks a while if no internet is available.
B) Connect to a Socket on the Internet (advanced)
// TCP/HTTP/DNS (depending on the port, 53=DNS, 80=HTTP, etc.)
public boolean isOnline() {
try {
int timeoutMs = 1500;
Socke...
How to decide font color in white or black depending on background color?
...ine the overall intensity of the color and choose the corresponding text.
if (red*0.299 + green*0.587 + blue*0.114) > 186 use #000000 else use #ffffff
The threshold of 186 is based on theory, but can be adjusted to taste. Based on the comments below a threshold of 150 may work better for you.
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Limit the length of a string with AngularJS
...on () {
return function (value, wordwise, max, tail) {
if (!value) return '';
max = parseInt(max, 10);
if (!max) return value;
if (value.length <= max) return value;
value = value.substr(0, max);
if (wordwise) {
...
Enter triggers button click
...lt;input type="submit"> . The buttons appear on the page in that order. If I'm in a text field anywhere in the form and press <Enter> , the button element's click event is triggered. I assume that's because the button element sits first.
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Java: Get first item from a collection
If I have a collection, such as Collection<String> strs , how can I get the first item out? I could just call an Iterator , take its first next() , then throw the Iterator away. Is there a less wasteful way to do it?
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How do I quickly rename a MySQL database (change schema name)?
...ne;
Notes:
There is no space between the option -p and the password. If your database has no password, remove the -u username -ppassword part.
If some table has a trigger, it cannot be moved to another database using above method (will result Trigger in wrong schema error). If that is the case...
How to wait for a keypress in R?
... readline(). Simply write:
readline(prompt="Press [enter] to continue")
If you don't want to assign it to a variable and don't want a return printed in the console, wrap the readline() in an invisible():
invisible(readline(prompt="Press [enter] to continue"))
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Preloading images with jQuery
...r a quick and easy way to preload images with JavaScript. I'm using jQuery if that's important.
20 Answers
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How do you reindex an array in PHP?
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If you want to re-index starting to zero, simply do the following:
$iZero = array_values($arr);
If you need it to start at one, then use the following:
$iOne = array_combine(range(1, count($arr)), array_values($arr));
H...
C++ new int[0] — will it allocate memory?
... pointer returned as a request for zero size is undefined.
Also
Even if the size of the space requested [by new] is zero, the request can fail.
That means you can do it, but you can not legally (in a well defined manner across all platforms) dereference the memory that you get - you can only...