is_numeric()

Examples of is_numeric()

Example 1

<?php
$num = 1;
if ( is_numeric($num) ) {
    echo $num . ' is a number!';
}
else {
    echo $num . ' is not a number. Shame!';
}

The above will output “1 is a number!” because $var is the number 1.

Example 2

<?php
$string = '1234';
if ( is_numeric($string) ) {
    echo $string. ' is a number!';
}
else {
    echo $string . ' is not a number. Shame!';
}

The above will output “1234 is a number!”. Although 1234 is a string, it is a numeric string and is_numeric() evaluates it to true.

Example 3: is_numeric() with Dashes and Underscores.

<?php
$string = '1-2';
if ( is_numeric($string) ) {
    echo $string. ' is a number!';
}
else {
    echo $string . ' is not a number. Shame!';
}

The above will output “1-2 is not a number. Shame!”. Underscores and commas will also produce a false result.

Example 4: is_numeric() with Periods

<?php
 $float = '52.2565';
 if ( is_numeric($float) ) {
     echo $float. ' is a number!';
 }
 else {
     echo $float. ' is not a number. Shame!';
 }

The above will output “52.2565 is a number!”. Floats are decimal numbers and evaluate to true. More than one period will cause is_numeric() to return false.