How to check if a number falls in a given range - php

Question

I have a variable $user_id (number value)
Want to check if $user_id falls in between the range of 1 - 1000 or 1001 - 2000 or 2001 - 3000 .... 99001 - 100000
Is there a way to do this without writing 100 switch or if statements in PHP?
When it finds the match, execute a code.
I know while and for loops are required for this. But not able to code it properly.

Answer 1

This the simplest way:
$check = 0;
$nextCheck = $check+1001;
while ($check < 100001) {
If ($user_id > $check && $user_id < $nextCheck) {
// Code ...
break;
} else {
$check+=1000;
$nextCheck+=1000;
}
}

Answer 2

You can just divide the number by 1000 since you have a 1000 interval range in a consecutive way.
The quotient * 1000 + 1 is your start value for the interval with an exceptional corner case of a number divisible by 1000, which would just be the border end for an interval.
<?php
$tests = [1,999,1000,50001,100000,2999];
foreach($tests as $test_case){
$quotient = intval($test_case / 1000);
if($test_case % 1000 === 0){
$start = $test_case - 1000 + 1;
echo "$test_case : Range: ($start - $test_case)",PHP_EOL;
}else{
$start = $quotient * 1000 + 1;
$end = ($quotient + 1) * 1000;
echo "$test_case : Range: ($start - $end)",PHP_EOL;
}
}
Output:
1 : Range: (1 - 1000)
999 : Range: (1 - 1000)
1000 : Range: (1 - 1000)
50001 : Range: (50001 - 51000)
100000 : Range: (99001 - 100000)
2999 : Range: (2001 - 3000)
Demo: https://3v4l.org/apbqV

Answer 3

Do not generate an array. Do not use a loop. Use math to determine the upper limit of the range, then subtract 999 from that number -- done.
*my snippet assumes we are only dealing with positive values between 1 and 100000.
Code: (Demo)
$tests = [1, 999, 1000, 50001, 100000, 2999];
foreach ($tests as $test) {
$upper = intval(($test - 1) / 1000) * 1000 + 1000;
echo "$test is between " . ($upper - 999) . " and $upper\n";
}
Output:
1 is between 1 and 1000
999 is between 1 and 1000
1000 is between 1 and 1000
50001 is between 50001 and 51000
100000 is between 99001 and 100000
2999 is between 2001 and 3000
Formula Breakdown:
intval( #3) remove decimals from difference
($test - 1) #1) subtract one
/ 1000 #2) divide by 1000
)
* 1000 #4) multiply integer by 1000
+ 1000 #5) add 1000