The use and difference between intval and int conversion under initializecriticalsection php

Copy code The code is as follows:

echo "
Value cast:";
$string="2a";
$string1=intval($string);
echo 'The value of $string1:'.$string1.'The value of $string2:';//Single quotes will not output the variable, and will be output as is
$string2=(int)($string);
echo $string2
?>

Can’t be found in the manual.
This is also what the manual says: Quote:
int intval (mixed $var [, int $base])
Returns the integer value of the variable var by using a specific base conversion (the default is decimal). If there is only this difference, then I like to use (int) to deal with decimal situations. Is it a good choice?
No difference, generally use (int), there are also float, string, array, etc.
intval(), if the parameter is a string, returns the number string before the first character in the string that is not a number The integer value represented. If the first character in the string is ‘-’, counting starts from the second character.
If the parameter is a dot number, its rounded value will be returned.
Of course, the value returned by intval() is within the range that can be represented by a 4-byte value (-2147483648~2147483647). Values ​​exceeding this range will be replaced by boundary values.
Example: intval("A")=0; intval(12.3223)=12; intval("1123Asdfka3243")=1123;
int();
Example:
$a=0.13;
$b=(int)$ a; //$b=0;
$a=0.99;
$b=(int)$a; //$b=0;
$a=1.01;
$b=(int)$a; // $b=1;
$a=1.99;
$b=(int)$a; //$b=1;
PHP string to int conversion Sometimes, it is important to have the value of a variable in int format. eaxmple, if your visitor fills out the form with the age field, this should be an int. However, in the $_POST array, you are getting it as a string.
Converting PHP string to int is easy. We need to use your variable type before casting.So you need to use (INT). Here is an example of how to do this:

Copy code The code is as follows:

$str = "10";
$num = (int)$str;?>

If you want to check that the code REALLY works, we can use the === operator. This operator checks not only the value, but the type as well. Such code should look like this:

Copy code The code is as follows:

$str = "10";
$num = (int)$str;
if ($ str === 10) echo "String";
if ($num === 10) echo "Integer";
?>

There is another question open. What happens if our string is not simply a string of numbers. I mean there are other characters in the string. In this case, the conversion operation tries the best and can convert the string if only space is there and if there are no valid characters after the numeric value. It works like this:
"10" - > 10
"10.5" - > 10
"10,5" - > 10
"10" - > 10
"10" - > 10
" 10test" - > 10
"test10" - > 0
The above introduces the use and difference between intval and int conversion under initializecriticalsection PHP, including the content of initializecriticalsection. I hope it will be helpful to friends who are interested in PHP tutorials.