How to determine whether a variable is a decimal and it is less than 0.01 in PHP?
H开发者_开发知识库ow to determine whether a variable is a decimal and it is less than 0.01 in PHP? If I write
if($balance<0.01)
Will a
true
value be returned if
$balance
is not a decimal at all?
use if( is_numeric($balance) && $balance < 0.01 )
http://php.net/manual/de/function.is-numeric.php
The value of $balance
will be typecasted to whatever is needed for the comparison. In your case, any integer will do, e.g. a $balance of 1
, 1.1
or '1'
will all evaluate to false
, regardless of their initial type. Consequently 0 < 0.1
will evaluate to true
, because it will not check the type.
See the PHP manual on Comparison Operators, type juggling and the type comparison table. Also, See these functions for checking types
is_int()
to find whether the type of a variable is integeris_float()
to find whether the type of a variable is float/decimal
Example:
var_dump(is_int(1)); // true
var_dump(is_int(1.0)); // false
var_dump(is_int(1.1)); // false
var_dump(is_int('1')); // false
var_dump(is_float(1)); // false
var_dump(is_float(1.0)); // true
var_dump(is_float(1.1)); // true
var_dump(is_float('1')); // false
Out of curiosity, wouldn't it be easier to just check for if(!($balance > 0))
?
Use the is_real() function:
if(is_real($balance) && $balance<0.01)
{
...
}
To answer your question, which was a straight forward yes/no: it depends.
If it's any type of number, like float, double or integer then php will perform as expected. Even if it's a string that php can interpret as a number, that'll work. If it's any other string like just $balance = "whatever", then this will return true so you would do a type checking if you expect this, in the fashion suggested by the other answers.
See the manual for more examples on what different operands produce.
try is_float()
<?php
$balance=2.75;
if(is_float($val) && $balance<0.01) {
echo "is decimaland less than 0.01 \n";
}else {
echo "is not decimal and greater than 0.01 \n";
}
http://www.php.net/manual/en/function.is-float.php
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