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What does the PHP error message “Notice: Use of undefined constant” mean?
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You should quote your array keys:
$department = mysql_real_escape_string($_POST['department']);
$name = mysql_real_escape_string($_POST['name']);
$email = mysql_real_escape_string($_POST['email']);
$message = mysql_real_escape_string($_POST['mess...
GET URL parameter in PHP
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$_GET is not a function or language construct—it's just a variable (an array). Try:
<?php
echo $_GET['link'];
In particular, it's a superglobal: a built-in variable that's populated by PHP and is available in all scopes (you can use it from inside a function without the global keyword).
S...
Clean ways to write multiple 'for' loops
For an array with multiple dimensions, we usually need to write a for loop for each of its dimensions. For example:
16 An...
Is Fortran easier to optimize than C for heavy calculations?
...ounterpart after optimization. Why so? If you write values into the output array, you may change the values of matrix. After all, the pointers could overlap and point to the same chunk of memory (including the int pointer!). The C compiler is forced to reload the four matrix values from memory for a...
Extract first item of each sublist
...my favorite) use numpy:
>>> import numpy as np
>>> a=np.array([[1,2,3],[11,12,13],[21,22,23]])
>>> a
array([[ 1, 2, 3],
[11, 12, 13],
[21, 22, 23]])
>>> a[:,0]
array([ 1, 11, 21])
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Generate unique random numbers between 1 and 100
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For example: To generate 8 unique random numbers and store them to an array, you can simply do this:
var arr = [];
while(arr.length < 8){
var r = Math.floor(Math.random() * 100) + 1;
if(arr.indexOf(r) === -1) arr.push(r);
}
console.log(arr);
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Multidimensional Array [][] vs [,] [duplicate]
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One is an array of arrays, and one is a 2d array. The former can be jagged, the latter is uniform.
That is, a double[][] can validly be:
double[][] x = new double[5][];
x[0] = new double[10];
x[1] = new double[5];
x[2] = new double...
Why are elementwise additions much faster in separate loops than in a combined loop?
...nk/way conflicts.
If I've guessed correctly on how you are allocating your arrays, they are likely to be aligned to the page line.
This means that all your accesses in each loop will fall on the same cache way. However, Intel processors have had 8-way L1 cache associativity for a while. But in reali...
Append a NumPy array to a NumPy array
I have a numpy_array. Something like [ a b c ] .
9 Answers
9
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Reset keys of array elements in php?
The question is how to reset key e.g. for an array:
6 Answers
6
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