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(Built-in) way in JavaScript to check if a string is a valid number
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To check if a variable (including a string) is a number, check if it is not a number:
This works regardless of whether the variable content is a string or number.
isNaN(num) // returns true if the variable does NOT contain a...
Fastest way to check if a value exists in a list
What is the fastest way to know if a value exists in a list (a list with millions of values in it) and what its index is?
1...
How to redirect output to a file and stdout
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The command you want is named tee:
foo | tee output.file
For example, if you only care about stdout:
ls -a | tee output.file
If you want to include stderr, do:
program [arguments...] 2>&1 | tee outfile
2>&1 redirects channel 2 (stderr/standard error) into channel 1 (stdout/s...
How to search by key=>value in a multidimensional array in PHP
...ode:
function search($array, $key, $value)
{
$results = array();
if (is_array($array)) {
if (isset($array[$key]) && $array[$key] == $value) {
$results[] = $array;
}
foreach ($array as $subarray) {
$results = array_merge($results, sea...
How to read if a checkbox is checked in PHP?
How to read if a checkbox is checked in PHP?
18 Answers
18
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break out of if and foreach
I have a foreach loop and an if statement. If a match is found i need to ultimately break out of the foreach.
4 Answers
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How to fix Array indexOf() in JavaScript for Internet Explorer browsers
If you have worked with JavaScript at any length you are aware that Internet Explorer does not implement the ECMAScript function for Array.prototype.indexOf() [including Internet Explorer 8]. It is not a huge problem, because you can extend the functionality on your page with the following code.
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Split List into Sublists with LINQ
...By(x=>f(x)).First() will never yield a group. OP asked about lists, but if we write to work with IEnumerable, making only a single iteration, we reap the performance advantage.
– Colonel Panic
Jul 11 '12 at 22:16
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Switch statement: must default be the last case?
...ice:
Any statement may be preceded by a
prefix that declares an identifier as
a label name. Labels in themselves do
not alter the flow of control, which
continues unimpeded across them.
Edit: The code within a switch is nothing special; it is a normal block of code as in an if-stateme...
Convert light frequency to RGB?
...(double Wavelength) {
double factor;
double Red, Green, Blue;
if((Wavelength >= 380) && (Wavelength < 440)) {
Red = -(Wavelength - 440) / (440 - 380);
Green = 0.0;
Blue = 1.0;
} else if((Wavelength >= 440) && (Wavelength < 490)) {
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