PHP - Counting array elements in a specific range - php

Question

I have an array with 950 elements. Values of elements are between 80-110. I want to count how many of them between 80-90, 90-100 and 100-110. Then I'll show them on a graph. Is this possible to count elements like that in php ?

Answer 1

You can simply do it by running a for loop. Create an array containing a range of elements and run a for loop. While you will run the loop on that time count the array element according to your given three groups. Finally you will get the total number of elements inside the given range. For your better help below I am giving an example :
<?php
$number = array(80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110);
$count1 = $count2 = $count3 = 0;
for ($i = 0; $i < sizeof($number); $i++) {
if($number[$i] >= 80 && $number[$i] <= 90 ) {
$count1++;
}
if($number[$i] >= 90 && $number[$i] <= 100 ) {
$count2++;
}
if($number[$i] >= 100 && $number[$i] <= 110 ) {
$count3++;
}
}
echo "The number between 80-90 = ".$count1."<br>";
echo "The number between 90-100 = ".$count2."<br>";
echo "The number between 100-110 = ".$count3."<br>";
?>

Answer 2

I think OP may have been going for a more pythonic answer (but in PHP)
//only valid in php 5.3 or higher
function countInRange($numbers,$lowest,$highest){
//bounds are included, for this example
return count(array_filter($numbers,function($number) use ($lowest,$highest){
return ($lowest<=$number && $number <=$highest);
}));
}
$numbers = [1,1,1,1,2,3,-5,-8,-9,10,11,12];
echo countInRange($numbers,1,3); // echoes 6
echo countInRange($numbers,-7,3); // echoes 7
echo countInRange($numbers,19,20); //echoes 0
the 'use' keyword indicates a 'closure' in php. Taken for granted in other languages, for example javascript, variables in an outer function are imported scope-wise into the inner function automatically (i.e. without special keywords), the inner function may also be called a "partial function".
For some reason in PHP 5.2x or lower, variables were not imported scope-wise automatically, and in PHP 5.3 or higher, the use keyword can overcome this. The syntax is very simple:
$functionHandle = function(<arguments>) use (<scope-imported variables>){
//...your code here...
}

Answer 3

To avoid having too many comparisons jump to next loop when you have determined where your number belongs.
function countOccurences( array $numbersArray ):array
{
$return = array('n80to90' => 0, 'n90to100' => 0, 'n100to110' => 0);
foreach( $numbersArray as $number ){
if( $number < 80 || $number > 110 )
continue;
if($number < 91){
$return['n80to90']++;
continue;
}
if($number < 101){
$return['n90to100']++;
continue;
}
$return['n100to110']++;
}
return $return;
}

Answer 4

I cannot imagine that your statistical graphic that would want to represent values on the cusp of two groups as belonging to both groups. For this reason, I'll offer a condition-less function-less technique which can be execute in a foreach loop.
Code: (Demo)
$sampleData = range(80, 110);
$result = array_fill_keys(['80s', '90s', '100s'], 0); // set 0 defaults for incrementation
foreach ($sampleData as $value) {
++$result[(10 * ((int)($value / 10) <=> 9) + 90) . 's'];
}
var_export($result);
Output:
array (
'80s' => 10,
'90s' => 10,
'100s' => 11,
)
My technique manufactures the appropriate keys from the values by:
Dividing by 10
Truncating the decimal (same effect as floor()
Making a 3-way comparison via the spaceship operator (returns -1, 0, or 1)
Multiplying the "-1|0|1" by 10
Adding 90
And finally concatenating an "s".
The ++ means add 1 to the current value of the element with the corresponding key.
Alternatively, if you wanted to group the values as "90+below" (80-90), "100+below" (91-100), and "110+below" (101-110), then it is a simple matter of adjusting the key-generating factors.
Instead of counting, I'll show the elements assigned to each group.
Code: (Demo)
$sampleData = range(80, 110);
foreach ($sampleData as $value) {
$result[(10 * ((int)(($value - 1) / 10) <=> 9) + 100) . '+under'][] = $value;
}
var_export($result);
Output:
array (
'90+under' =>
array (
0 => 80,
1 => 81,
2 => 82,
3 => 83,
4 => 84,
5 => 85,
6 => 86,
7 => 87,
8 => 88,
9 => 89,
10 => 90,
),
'100+under' =>
array (
0 => 91,
1 => 92,
2 => 93,
3 => 94,
4 => 95,
5 => 96,
6 => 97,
7 => 98,
8 => 99,
9 => 100,
),
'110+under' =>
array (
0 => 101,
1 => 102,
2 => 103,
3 => 104,
4 => 105,
5 => 106,
6 => 107,
7 => 108,
8 => 109,
9 => 110,
),
)