How to remove integers in array less than X? - php

Question

I have an array with integers of values from 0 to 100. I wish to remove integers that are less than number X and keep the ones that are equal or greater than number X.

Answer 1

A little ugly using the clunky create_function, but straight forward:
$filtered = array_filter($array, create_function('$x', 'return $x >= $y;'));
For PHP >= 5.3:
$filtered = array_filter($array, function ($x) { return $x >= $y; });
Set $y to whatever you want.

Answer 2

Smarter than generating an array that is too big then cutting it down to size, I recommend only generating exactly what you want from the very start.
range() will do this job for you without the bother of an anonymous function call iterating a condition.
Code: (Demo)
$rand=rand(0,100); // This is your X randomly generated
echo $rand,"\n";
$array=range($rand,100); // generate an array with elements from X to 100 (inclusive)
var_export($array);
Potential Output:
98
array (
0 => 98,
1 => 99,
2 => 100,
)
Alternatively, if you truly, truly want to modify the input array that you have already generated, then assuming you have an indexed array you can use array_slice() to remove elements using X to target the starting offset and optionally preserve the indexes/keys.
Code: (Demo)
$array=range(0,100);
$rand=rand(0,100); // This is your X randomly generated
echo $rand,"\n";
var_export(array_slice($array,$rand)); // reindex the output array
echo "\n";
var_export(array_slice($array,$rand,NULL,true)); // preserve original indexes
Potential Output:
95
array (
0 => 95,
1 => 96,
2 => 97,
3 => 98,
4 => 99,
5 => 100,
)
array (
95 => 95,
96 => 96,
97 => 97,
98 => 98,
99 => 99,
100 => 100,
)