Verify that the user input number is in the specified range

/*
JS Verification
<script type= "Text/javascript Tutorial" >
var Dnum=document.getelementbyid ("Fenshu");
Dnum.onkeyup = function () {
This.value=this.value.replace (/d/g, "");
if (dnum.value>1000| | DNUM.VALUE<100) {
dnum.value=100;
}
}
</script>
*/

PHP Tutorial Validation
$var = 300;

$int _options = Array (
"Options" =>array
(
"Min_range" =>0,
"Max_range" =>256
)
);

if (!filter_var ($var, Filter_validate_int, $int _options))
{
Echo ("Integer is not valid");
}
Else
{
Echo ("Integer is valid");
}

Method Three JS

var reg =/d{2,3}/;
var s = 888;
Alert (Reg.test (s));

PHP Regular

^ ([1-9][0-9][0-9]|1000) $

/*
Here we use the regular expression to complete, verify that the number is between the specified data spacing.
*/
?>