Round My number?
I have an number
$n = -5665.36
$round_set = can be : 1,10,10,100,1000
use the $round_set condition to get the $m
if $round_set = 1
$m = $n
if $round_set = 10
$m = -5660
if $round_set = 100
$m = -5600
if $round_set = 1000
$m = -5000
Anybody know how to round these kind of case?
Use this
intval($m/$round_set) * $round_set
http://codepad.viper-7.com/1EHFWEJ test it here.
<?php
$n = -5665.36;
$round_set = 100;
$precision = -log10($round_set);
$m = ($round_set == 1 ? $n : round($n, $precision) + $round_set);
echo $m;
?>
Wouldn't something like this work?
function rounded_nb($number, $round_set) {
return floor($number/$round_set)*$round_set;
}
For any non 0 $round_set ?
You don't need the switch, do
if($round_set > 0) {
$rounded = $round_set * floor($n / $round_set);
} else {
$rounded = $n;
}
This should pretty much do.
$rs1 = max(1, $round_set);
$m = $rs1 * floor($n / $rs1);
However a 1,10,100,... valued $round_set might make more sense.
Why not take advantage of PHP's round
$m = round($n, ($round_set == 0 ? 0 : -1 * log10($round_set)) );
Edit: Corrected edge-case of log10(0).
Edit 2: Corrected the precision.
Related
I need to validate that an inputted number is a valid number based on my stepping rules and round up to the nearest valid number if not. These numbers will change but one example would be:
$min = 0.25;
$step = 0.1
$qty = 0.75 // user input
so these would be valid inputs:
0.75
0.85
0.95
But these should round:
0.76 (to 0.85)
0.80 (to 0.85)
I thought I could use modulus somehow but not getting the calculation correct.
if (($qty % min) / $step == 0)) {
echo "good";
}
I've tried some variations of math that are likely very wrong
$step = 0.1;
$min = 0.25;
$qty = .85;
$h = ($qty / $min) / $step;
echo $h;
$j = mround($qty, $min-$step);
echo $j;
function mround($num, $parts) {
if ($parts <= 0) { $parts = 1; }
$res = $num * (1/$parts);
$res = round($res);
return $res /(1/$parts);
}
I think you can use fmod to do this.
$new = $original + ($step - fmod($original - $minimum, $step));
Example on 3v4l.org
I want to create a function in which I put two values (value and its power - Example function: multiply(3, 3) result 27). I have tried so far but failed, I have searched using Google but I have been unable to find any result because I don't know the name of this function.
What I want exactly:
3,3 => 3 x 3 x 3 = 27
4,4 => 4 x 4 x 4 x 4 = 256
What I tried:
function multiply($value,$power){
for($x = 1; $x <= $value; $x++ ){
return $c = $value * $power;
}
}
echo multiply(3,3);
The answer has already been accepted, but I had to come here and say that all answers here use a bad algorithm. There are better ones. Including very simple ones, like exponentiation by squaring that reduces the complexity from O(power) to O(log(power)).
The idea is to square the base while dividing the exponent by 2. For example
3^8 = 9^4 = 81^2 = 6561
There is a special case when the exponent is odd. In this case, you must store a separate variable to represent this factor:
2^10 = 4^5 = 16^2 * 4 = 256 * 4 = 1024
PHP isn't one of my strong skills, but the final algorithm is as simple as:
function multiply($value, $power){
$free = 1;
while ($power > 1) {
if ($power % 2 == 1)
$free *= $value;
$value *= $value;
$power >>= 1; //integer divison by 2
}
return $value*$free;
}
echo multiply(3, 3) . "\n";
echo multiply(2, 10) . "\n";
echo multiply(3, 8) . "\n";
Oopsika, couldn't have asked a more obvious question. Use the built-in function named pow (as in a lot of languages)
echo pow(3, 3);
Edit
Let's create our own function.
function raiseToPower($base,$exponent)
{
// multiply the base to itself exponent number of times
$result=1;
for($i=1;$i<=$exponent;$i++)
{
$result = $result * $base;
}
return $result;
}
function exponent($value,$power)
{
$c=1;
for($x = 1; $x <= $power; $x++ )
{
$c = $value * $c;
}
return $c;
}
If you have PHP >= 5.6 you can use the ** operator
$a ** $b Exponentiation Result of raising $a to the $b'th power.
echo 2 ** 3;
If you have PHP < 5.6 you can use pow:
number pow ( number $base , number $exp )
echo pow(2, 3);
Your own function is:
function multiply($value, $power) {
$result = 1;
for($x = 1; $x <= $power; $x++){
$result *= $value;
}
return $result;
}
echo multiply(3,3);
Read more at:
http://php.net/manual/en/language.operators.arithmetic.php
http://php.net/manual/en/function.pow.php
Just try to run this code I hope your problem will be solved.
If you defining any function then you have to call it return value.
<?php
function multiply($value,$exp)
{ $temp=1;
if($exp==0)
return $temp;
else
{
for($i=1;$i<=$exp;$i++)
$temp=$temp*$value;
return $temp;
}
}
echo multiply(5,6);
?>
echo "Enter number (will be mutiplied):".PHP_EOL;
$value = (int) readline("> ");
echo "Enter number for multiplier:".PHP_EOL;
$multiplier = (int) readline("> ");
function power(int $i, int $n):int {
$result =1;
for ($int = 1; $int < $n; $int++){
$result *= $i;
}
return $result;
}
echo power($value,$multiplier);
I have a value, lets say its 1000.
Now I have to generate a random minus or plus percentage of 1000.
In particular I have to generate or a -20% of 1000 or a +20% of 1000 randomly.
I tried using rand() and abs() but with no success..
Is there a way in PHP to achieve the above?
A bit of basic mathematics
$number = 1000;
$below = -20;
$above = 20;
$random = mt_rand(
(integer) $number - ($number * (abs($below) / 100)),
(integer) $number + ($number * ($above / 100))
);
rand(0, 1) seems to work fine for me. Maybe you should make sure your percentage is in decimal format.
<?php
$val = 10000;
$pc = 0.2;
$result = $val * $pc;
if(rand(0, 1)) echo $result; else echo -$result;
if(rand(0, 1)) echo $result; else echo -$result;
if(rand(0, 1)) echo $result; else echo -$result;
if(rand(0, 1)) echo $result; else echo -$result;
if(rand(0, 1)) echo $result; else echo -$result;
?>
$number = 10000;
$percent = $number*0.20;
$result = (rand(0,$percent)*(rand(0,1)*2-1));
echo $result;
Or if you want some sort of running balance type thing....
function plusminus($bank){
$percent = $bank*0.20;
$random = (rand(0,$percent)*(rand(0,1)*2-1));
return $bank + $random;
}
$new = plusminus(10000);
$new = plusminus($new);
echo $new."<br>";
$new = plusminus($new);
echo $new."<br>";
$new = plusminus($new);
echo $new."<br>";
$new = plusminus($new);
echo $new."<br>";
$new = plusminus($new);
echo $new."<br>";
$new = plusminus($new);
I know this is really old now but stumbled across it looking for something similar where I needed a random sign (+ or -) so opted for a random boolean:
<?php $sign = (rand(0,1) == 1) ? '+' : '-'; ?>
Thanks to this this answer.
So I would opt for a solution like this:
<?php
// Alter these as needed
$number = 1000;
$percentage = 20;
// Calculate the change
$change_by = $number * ($percentage / 100);
// Set a boolean at random
$random_boolean = rand(0,1) == 1;
// Calculate the result where we are using plus if true or minus if false
$result = ($random_boolean) ? $number + $change_by : $number - $change_by;
// Will output either 1200 or 800 using these numbers as an example
echo $result;
?>
I want to generate alphanumeric unique numbers but the format should be like this
that should be starts from AA001 to AA999 after that AB001 to AB999 .... BA001 to BA999 end with ZZ999. if i give the input is
1 = result AA001
999 = result AA999
1000 = result AB001
any one can help this ?
Complete solution (see it running):
function formatNum1000($num) {
$tail = $num % 1000;
$head = (int)($num / 1000);
$char1 = chr(ord('A') + (int)($head / 26));
$char2 = chr(ord('A') + ($head % 26));
return sprintf('%s%s%03d', $char1, $char2, $tail);
}
function formatNum999($num) {
$tail = (($num - 1 ) % 999) + 1;
$head = (int)(($num - $tail) / 999);
$char1 = chr(ord('A') + (int)($head / 26));
$char2 = chr(ord('A') + ($head % 26));
return sprintf('%s%s%03d', $char1, $char2, $tail);
}
$ns = array(1, 500, 999, 1000, 1998, 1999, 2000, 25974, 25975, 25999, 26000, 675324, 675999);
foreach($ns as $n) {
$formatted1000 = formatNum1000($n);
$formatted999 = formatNum999 ($n);
echo "Num: $n => $formatted1000 / $formatted999\n";
}
Note: you need to make sure that the input number is within the valid range (0...675999 when including 000-numbers, 1...675324 otherwise)
Note: answer revised, missed the point earlier that 000 is not allowed
How about:
$start = 'AA997';
for($i = 0; $i < 5; $i++) {
$start++;
if (substr($start, 2) == '000') continue;
echo $start,"\n";
}
output:
AA998
AA999
AB001
AB002
How can I solve this problem:
if ($variable == 1) {
$math = "-";
} else {
$math = "+";
}
$numberOne = 10;
$numberTwo = 10;
$result = $numberOne $math $numberTwo;
This doesn´t work, is there any way to solve this?
This will work for your example. A subtraction is the same as adding a negative. This will be far safer than the alternative of using eval.
if ($variable == 1) {
$modifier = -1;
} else {
$modifier = 1;
}
$numberOne = 10;
$numberTwo = 10;
$result = $numberOne + ($numberTwo * $modifier);
I suppose you could use eval() -- but that would be quite a bad idea (it would not be good for performances, it's not "clean", ...)
In this kind of situation, I would generally go with a switch on the operator, and one case per possible operator.
Here, it would mean using something like this :
switch ($math) {
case '+':
$result = $numberOne + $numberTwo;
break;
case '-':
$result = $numberOne - $numberTwo;
break;
}
Which can easily be extends to other operators.
(In your specific situation, if you only have + and -, though, some calculation based on a multiplication by +1 or -1 would be faster to write)
if ($variable == 1) {
$math = -1; // subtraction
} else {
$math = 1; // addition
}
$numberOne = 10;
$numberTwo = 10;
$result = $numberOne + ($math * $numberTwo);
No love for the ternary operator?
To minify Gazler's answer a bit further:
$modifier = ($variable == 1) : -1 ? 1;
$numberOne = 10;
$numberTwo = 10;
$result = $numberOne + ($numberTwo*$modifier);
If you plan to use more complex mathematics, you can use the eval() function.