php check number or not code example

Example 1: is number divisible by 3 php

if($number % 15 == 0)  {
    echo "BY3 AND 5";
} elseif ($number % 5 == 0) {
    echo "BY5";
} elseif ($number % 3 == 0) {
    echo "BY3";
}

Example 2: check if string is number or not php

$var_num = "1";
$var_str = "Hello World";

var_dump( is_numeric($var_num), is_numeric($var_str) );

/* 
Output -
 bool(true)
 bool(false)
*/

Example 3: check number is positive or negative in php

if($number > 0){
  echo "the number is positive";
}
elseif($number < 0){
  echo "the number is negative";
}
else{
  echo "the number is zero";
}