PHP

php is numeric

//is_numeric — Finds whether a variable is a number or a numeric string
is_numeric ( $variable ); // returns true or false

php is variable a number

if(is_numeric($what_am_i)){
	//true
}  

php check if variable is int

// Check if variable is int
$id = "1";

if(!intval($id)){
  throw new Exception("Not Int", 404);
}
else{
	// this variable is int
}

php check string is int

<?php
// combination of is_int and type coercion
// FALSE: 0, '0', null, ' 234.6',  234.6
// TRUE: 34185, ' 34185', '234', 2345
$mediaID =  34185;
if( is_int( $mediaID + 0) && ( $mediaID + 0 ) > 0 ){
    echo 'isint'.$mediaID;
}else{
    echo 'isNOTValidIDint';
}
?>

php is int

is_int(mixed $value): bool

php is_int

<?php
$values = array(23, "23", 23.5, "23.5", null, true, false);
foreach ($values as $value) {
    echo "is_int(";
    var_export($value);
    echo ") = ";
    var_dump(is_int($value));
}
?>
  
/* Output
is_int(23) = bool(true)
is_int('23') = bool(false)
is_int(23.5) = bool(false)
is_int('23.5') = bool(false)
is_int(NULL) = bool(false)
is_int(true) = bool(false)
is_int(false) = bool(false)
*/
 

php check if string is integer

<?php
$strings = array('1820.20', '10002', 'wsl!12');
foreach ($strings as $testcase) {
    if (ctype_digit($testcase)) {
        echo "The string $testcase consists of all digits.
";
    } else {
        echo "The string $testcase does not consist of all digits.
";
    }
}
?>