CODEWITHSUNDEEP
phpvalidationfloating-point
rkt
rkt

Reputation: 1181

checking if a number is float in PHP

This is really weird. I have this piece of code.

$rewardAmt = $amt;
if(is_float($rewardAmt)){
      print_r("is float");die;
} else {
      print_r("is not float"); die;
}

value of $amt is 0.01. But it is going into else condition. So I did a var_dump of $amt. it says string(4) So I decided to typecast $amt 

   $rewardAmt = (float)$amt;

But the problem with this is even if the value of $amt is 1, it still gets typecast to float and goes into if condition, which shouldn't happen. Is there any other way to do this ? Thanks

Upvotes: 8

Views: 14773

Answers (5)

Rickyx
Rickyx

Reputation: 63

As suggested in the documentation of is_float function:

Note: To test if a variable is a number or a numeric string (such as form input, which is always a string), you must use is_numeric().

The answer is using is_numeric() and not is_float(). This works also if the number tested is "0" or 0.

Upvotes: 0

trincot
trincot

Reputation: 350127

You can use the unary + operator, which will cast the string to the appropriate type (int or float), and then test the resulting data type with is_float:

$s = "3.00";
$n = +$s;
var_dump( $n ); // float(3)
var_dump( is_float($n) ); // true


$s = "3";
$n = +$s;
var_dump( $n ); // int(3)
var_dump( is_float($n) ); // false

Upvotes: 1

akgola
akgola

Reputation: 225

You can check this by

$float = floatval($num); //Convert the string to a float
if($float && intval($float) != $float) // Check if the converted int is same as the float value...
{
    // $num is a float
}else{
    // $num is an integer
}

Upvotes: 1

PhoenixWing156
PhoenixWing156

Reputation: 392

If you change the first line to 

$rewardAmt = $amt+0;

$rewardAmt should be cast to a number.

Upvotes: 4

John Conde
John Conde

Reputation: 219804

Use filter_var() with FILTER_VALIDATE_FLOAT

if (filter_var($amount, FILTER_VALIDATE_FLOAT))
{
     // good
}

Upvotes: 14

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