Best way to check for positive integer (PHP)?

Question

I need to check for a form input value to be a positive integer (not just an integer), and I noticed another snippet using the code below:

$i = $user_input_v         


        

Answer 1

This's my solution, hope helpful :

if (is_numeric($i) && (intval($i) == floatval($i)) && intval($i) > 0)
   echo "positive integer";

i check if string is numeric, second check to sure it's integer and third to sure it positive

Answer 2

The first example is using round to verify that the input is an integer, and not a different numeric value (ie: a decimal).

is_int will return false if passed a string. See the PHP manual examples for is_int

Answer 3

To check for positive integer use:

$i = $user_input_value;
if (is_int($i) && $i > 0) {
  return true; //or any other instructions 
}

OR

$i = $user_input_value;
if (!is_int($i) || $i < 1) {
  return false; //or any other instructions 
}

Use the one that fits your purpose as they are the same. The following examples demonstrate the difference between is_numeric() and is_int():

is_numeric(0);     // returns true
is_numeric(7);     // returns true
is_numeric(-7);    // returns true
is_numeric(7.2);   // returns true
is_numeric("7");   // returns true
is_numeric("-7");  // returns true
is_numeric("7.2"); // returns true
is_numeric("abc"); // returns false

is_int(0);     // returns true
is_int(7);     // returns true
is_int(-7);    // returns true
is_int(7.2);   // returns false
is_int("7");   // returns false
is_int("-7");  // returns false
is_int("7.2"); // returns false
is_int("abc"); // returns false

Answer 4

I would do something like this:

if ((int) $i > 0) {
    // this number is positive
}

The number gets typecast to a positive or negative number depending on the minus sign being at the front. Then compares the typecast number to being greater than 0 to determine if the number is positive.

Answer 5

if(preg_match('/^[1-9]\d*$/',$i)) {
   //Positive and > 0
}

Answer 6

Laravel 4.2 Validation rule for positive number

It takes only positive numbers including float values.

public static $rules = array(
    'field_name' => 'required|regex:/^\d*\.?\d*$/'
);

e.g:20,2.6,06