is_float

(PHP 4, PHP 5)

is_float — 변수가 실수인지 확인합니다.

설명

bool is_float ( mixed $var )

var 가 float라면 TRUE, 아니라면 FALSE를 반환합니다.

Note: 변수가 숫자나 숫자 문자열(폼 입력 등은 항상 문자열입니다)인지 확인하려면, is_numeric()을 사용해야 합니다.

참고: is_bool(), is_int(), is_integer(), is_numeric(), is_string(), is_array(), is_object(),

is_int

is_double

Last updated: Sun, 25 Nov 2007

add a note User Contributed Notes
is_float

Boylett
20-Sep-2008 09:29


If you want to test whether a string is containing a float, rather than if a variable is a float, you can use this simple little function:



function isfloat($f) return ($f == (string)(float)$f);

ckelley at the ca - cycleworks dot com
14-Jul-2008 03:39


Personally, I use an implicit cast:



if( is_float($value+1) ){

    $value=sprintf("%.2f",$value);

}



Which turns 22.0000000 query result into 22.00 for display to users.

kshegunov at gmail dot com
31-Mar-2008 02:32


As celelibi at gmail dot com stated, is_float checks ONLY the type of the variable not the data it holds!



If you want to check if string represent a floating point value use the following regular expression and not is_float(),

or poorly written custom functions.



/^[+-]?(([0-9]+)|([0-9]*\.[0-9]+|[0-9]+\.[0-9]*)|

(([0-9]+|([0-9]*\.[0-9]+|[0-9]+\.[0-9]*))[eE][+-]?[0-9]+))$/

celelibi at gmail dot com
03-Mar-2008 08:31


Unlike others comment may let you think, this function tests *only* the type of the variable. It does not perform any other test.

If you want to check if a string represents a valid float value, please use is_numeric instead.

WHITE new media architects - Jeroen
10-Jan-2008 03:24


The above printed "is_true_float" function is not correct.

It gives wrong answers on the following tests:

is_true_float("-4,123"); # returns false

is_true_float("0,123");  # returns false



So I changed the function to correctly handle qouted negative floats and quoted floats near zero:



<?php



function is_true_float($mVal)

{

  return ( is_float($mVal)

           || ( (float) $mVal != round($mVal)

                || strlen($mVal) != strlen( (int) $mVal) )

              && $mVal != 0 );

}



?>

Kenaniah Cerny
06-Nov-2007 11:21


For those of you who have discovered that is_float() does not behave exactly the way you would expect it to when passing a string, here is a function that extends is_float properly report floating numbers given any sort of mixed variable.



<?php

function is_true_float($val){

    if( is_float($val) || ( (float) $val > (int) $val || strlen($val) != strlen( (int) $val) ) && (int) $val != 0  ) return true;

    else return false;

}

?>



<?php

//Tests

'4.0'       returns true

'2.1'       returns true

0           returns false

"0"         returns false

3.          returns true

13          returns false

"12"        returns false

3.53        returns true

?>



Enjoy

phper
25-Jan-2006 12:08


A better way to check for a certain number of decimal places is to use :



$num_dec_places = 2;

number_format($value,$num_dec_places);

kirti dot contact at gmail dot com
18-Oct-2005 11:18


To check a float only should contain certain number of decimal places, I have used this simple function below



<?

function is_deccount($number,$decimal=2){

    $m_factor=pow(10,$decimal);

    if((int)($number*$m_factor)==$number*$m_factor)

        return true;

    else

        return false;

 }    

?>

add a note

is_int

is_double

Last updated: Sun, 25 Nov 2007